<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva, formerly WebFilings-->
<!-- -->
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <roleRef roleURI="http://www.agnc.com/role/ConsolidatedBalanceSheets" xlink:href="agnc-20140630.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:href="agnc-20140630.xsd#ConsolidatedBalanceSheetsParentheticals" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ConsolidatedStatementOfStockholdersEquity" xlink:href="agnc-20140630.xsd#ConsolidatedStatementOfStockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="agnc-20140630.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="agnc-20140630.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstruments" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstruments" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfDerivativeInstrumentsNotDesignatedAsHedgesOnIncomeStatementDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsEffectOfDerivativeInstrumentsNotDesignatedAsHedgesOnIncomeStatementDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfForwardContractsDesignatedAsHedgesDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsEffectOfForwardContractsDesignatedAsHedgesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfInterestRateSwapsDesignatedAsHedgesDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsEffectOfInterestRateSwapsDesignatedAsHedgesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsNarrativeDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsRemainingInterestRateSwapTermDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsRemainingInterestRateSwapTermDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfDerivativesOutstandingNotDesignatedAsHedgingInstrumentsDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfDerivativesOutstandingNotDesignatedAsHedgingInstrumentsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfLongAndShortPositionOfDerivativeInstrumentsDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfLongAndShortPositionOfDerivativeInstrumentsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingForwardContractsDesignatedAsHedgingInstrumentsDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingForwardContractsDesignatedAsHedgingInstrumentsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsDesignatedAsHedgesInFutureDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsDesignatedAsHedgesInFutureDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsNotDesignatedAsHedgesDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsNotDesignatedAsHedgesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDesignatedAsHedgingInstrumentsDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDesignatedAsHedgingInstrumentsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingTbasDetails" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingTbasDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsTables" xlink:href="agnc-20140630.xsd#DerivativeAndOtherHedgingInstrumentsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/DocumentAndEntityInformation" xlink:href="agnc-20140630.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/FairValueMeasurements" xlink:href="agnc-20140630.xsd#FairValueMeasurements" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/FairValueMeasurementsDetails" xlink:href="agnc-20140630.xsd#FairValueMeasurementsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/FairValueMeasurementsTables" xlink:href="agnc-20140630.xsd#FairValueMeasurementsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/IncomeTaxes" xlink:href="agnc-20140630.xsd#IncomeTaxes" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/IncomeTaxesDetails" xlink:href="agnc-20140630.xsd#IncomeTaxesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/IncomeTaxesTables" xlink:href="agnc-20140630.xsd#IncomeTaxesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecurities" xlink:href="agnc-20140630.xsd#InvestmentSecurities" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesComponentsOfInvestmentSecuritiesDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesComponentsOfInvestmentSecuritiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesNarrativeDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfAgencySecuritiesEstimatedWeightedAverageLifeClassificationsDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesSummaryOfAgencySecuritiesEstimatedWeightedAverageLifeClassificationsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfChangesInAccumulatedOciForAvailableForSaleSecurityDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesSummaryOfChangesInAccumulatedOciForAvailableForSaleSecurityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfContinuousUnrealizedLossPositionsOfAvailableForSaleSecurityDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesSummaryOfContinuousUnrealizedLossPositionsOfAvailableForSaleSecurityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfInvestmentInAgencySecurityDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesSummaryOfInvestmentInAgencySecurityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfNetGainFromSaleOfAgencySecuritiesDetails" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesSummaryOfNetGainFromSaleOfAgencySecuritiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/InvestmentSecuritiesTables" xlink:href="agnc-20140630.xsd#InvestmentSecuritiesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsDetails" xlink:href="agnc-20140630.xsd#ManagementAgreementAndRelatedPartyTransactionsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsNotes" xlink:href="agnc-20140630.xsd#ManagementAgreementAndRelatedPartyTransactionsNotes" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsTables" xlink:href="agnc-20140630.xsd#ManagementAgreementAndRelatedPartyTransactionsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/Organization" xlink:href="agnc-20140630.xsd#Organization" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/OrganizationDetails" xlink:href="agnc-20140630.xsd#OrganizationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/PledgedAssetsDetails" xlink:href="agnc-20140630.xsd#PledgedAssetsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/PledgedAssetsNotes" xlink:href="agnc-20140630.xsd#PledgedAssetsNotes" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/PledgedAssetsPledgedAssetsDetails" xlink:href="agnc-20140630.xsd#PledgedAssetsPledgedAssetsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/PledgedAssetsTables" xlink:href="agnc-20140630.xsd#PledgedAssetsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebt" xlink:href="agnc-20140630.xsd#RepurchaseAgreementsAndOtherDebt" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtNarrativeDetails" xlink:href="agnc-20140630.xsd#RepurchaseAgreementsAndOtherDebtNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtRepurchaseAgreementsPolicies" xlink:href="agnc-20140630.xsd#RepurchaseAgreementsAndOtherDebtRepurchaseAgreementsPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtRepurchaseArrangementsAndWeightedAverageInterestRatesClassifiedByOriginalMaturitiesDetails" xlink:href="agnc-20140630.xsd#RepurchaseAgreementsAndOtherDebtRepurchaseArrangementsAndWeightedAverageInterestRatesClassifiedByOriginalMaturitiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtTables" xlink:href="agnc-20140630.xsd#RepurchaseAgreementsAndOtherDebtTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/StockholdersEquity" xlink:href="agnc-20140630.xsd#StockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/StockholdersEquityDetails" xlink:href="agnc-20140630.xsd#StockholdersEquityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/StockholdersEquityEquityOfferingsTables" xlink:href="agnc-20140630.xsd#StockholdersEquityEquityOfferingsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/StockholdersEquitySummaryOfFollowOnPublicOfferingsOfCommonStockDetails" xlink:href="agnc-20140630.xsd#StockholdersEquitySummaryOfFollowOnPublicOfferingsOfCommonStockDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SubsequentEventDetails" xlink:href="agnc-20140630.xsd#SubsequentEventDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SubsequentEventNotes" xlink:href="agnc-20140630.xsd#SubsequentEventNotes" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SubsequentEventTables" xlink:href="agnc-20140630.xsd#SubsequentEventTables" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="agnc-20140630.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SummaryOfSignificantAccountingPoliciesDetails" xlink:href="agnc-20140630.xsd#SummaryOfSignificantAccountingPoliciesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/SummaryOfSignificantAccountingPoliciesPolicy" xlink:href="agnc-20140630.xsd#SummaryOfSignificantAccountingPoliciesPolicy" xlink:type="simple" />
  <roleRef roleURI="http://www.agnc.com/role/UnauditedInterimConsolidatedFinancialStatements" xlink:href="agnc-20140630.xsd#UnauditedInterimConsolidatedFinancialStatements" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <definitionLink xlink:role="http://www.agnc.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_AB3B614A4EA54B715DD3A26D0BDDAA83" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:to="loc_us-gaap_StatementTable_AB3B614A4EA54B715DD3A26D0BDDAA83" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_BEEE2BCC77E7A0ADACECA26D0BDD40A3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_AB3B614A4EA54B715DD3A26D0BDDAA83" xlink:to="loc_dei_LegalEntityAxis_BEEE2BCC77E7A0ADACECA26D0BDD40A3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_5A6068D6F4FBDCCA2239A26D0BDD2F53_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_BEEE2BCC77E7A0ADACECA26D0BDD40A3" xlink:to="loc_dei_EntityDomain_5A6068D6F4FBDCCA2239A26D0BDD2F53_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_5A6068D6F4FBDCCA2239A26D0BDD2F53" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_BEEE2BCC77E7A0ADACECA26D0BDD40A3" xlink:to="loc_dei_EntityDomain_5A6068D6F4FBDCCA2239A26D0BDD2F53" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MortgageBackedSecuritiesMember" xlink:label="loc_us-gaap_MortgageBackedSecuritiesMember_01D1248BEC34E940E40DA26D0BDD5DA6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_5A6068D6F4FBDCCA2239A26D0BDD2F53" xlink:to="loc_us-gaap_MortgageBackedSecuritiesMember_01D1248BEC34E940E40DA26D0BDD5DA6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_5F16DC15CF3E26555D7AA26D0BDD09F6" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_AB3B614A4EA54B715DD3A26D0BDDAA83" xlink:to="loc_us-gaap_StatementScenarioAxis_5F16DC15CF3E26555D7AA26D0BDD09F6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_6DE1AFE1C16A5E0E9E26A26D0BDD3516_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_5F16DC15CF3E26555D7AA26D0BDD09F6" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_6DE1AFE1C16A5E0E9E26A26D0BDD3516_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_6DE1AFE1C16A5E0E9E26A26D0BDD3516" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_5F16DC15CF3E26555D7AA26D0BDD09F6" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_6DE1AFE1C16A5E0E9E26A26D0BDD3516" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:to="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue" xlink:label="loc_us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue_DCB52AE62EF4650B4B61A26D0BDD0963" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue_DCB52AE62EF4650B4B61A26D0BDD0963" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets" xlink:label="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_7CDD50CF5D739F47B28DA26D0BDDC748" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_7CDD50CF5D739F47B28DA26D0BDDC748" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue" xlink:label="loc_us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue_D9892F32B8B9A4A75453A26D0BDDABF5" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue_D9892F32B8B9A4A75453A26D0BDDABF5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesEquitySecurities" xlink:label="loc_us-gaap_MarketableSecuritiesEquitySecurities_D0C4E6E0EF6D726A2B77A26D0BDDCAD7" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_MarketableSecuritiesEquitySecurities_D0C4E6E0EF6D726A2B77A26D0BDDCAD7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_9445785DD94ED08CDB1BA26D0BDD0198" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_9445785DD94ED08CDB1BA26D0BDD0198" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_E95EDD5CC1A8CD71A621A26D0BDD01F1" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_E95EDD5CC1A8CD71A621A26D0BDD01F1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_D53CB59386A9D9D23688A26D0BDD71A2" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_DerivativeAssets_D53CB59386A9D9D23688A26D0BDD71A2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations" xlink:label="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_8B33B588A02BBFFE5083A26D0BDD36A9" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_8B33B588A02BBFFE5083A26D0BDD36A9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceivableUnderReverseRepurchaseAgreements" xlink:label="loc_agnc_ReceivableUnderReverseRepurchaseAgreements_6488F6E3099610B9B5CDA26D0BDDA9F7" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_agnc_ReceivableUnderReverseRepurchaseAgreements_6488F6E3099610B9B5CDA26D0BDDA9F7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell" xlink:label="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_0DD04A83F4C7A063729DA26D0CB8BB9C" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_0DD04A83F4C7A063729DA26D0CB8BB9C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GrossAmountOfRecognizedAssetsLiabilities" xlink:label="loc_agnc_GrossAmountOfRecognizedAssetsLiabilities_22F6D406CCD9EB654AB6A26D0BDD70EC" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_agnc_GrossAmountOfRecognizedAssetsLiabilities_22F6D406CCD9EB654AB6A26D0BDD70EC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssets" xlink:label="loc_us-gaap_OtherAssets_5E04642835530AAD8FE7A26D0BDD3863" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_OtherAssets_5E04642835530AAD8FE7A26D0BDD3863" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_0CE817D172F95866E7B1A26D0BDD368B" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_EC4F7C82D73995C59ACAA26D0BDD99DB" xlink:to="loc_us-gaap_Assets_0CE817D172F95866E7B1A26D0BDD368B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAbstract" xlink:label="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:to="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_A47F0256150AAE48D11BA26D0BDDAFA4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_A47F0256150AAE48D11BA26D0BDDAFA4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLongTermDebt" xlink:label="loc_us-gaap_OtherLongTermDebt_BF52C14D657B9B571E38A26D0BDDF277" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_OtherLongTermDebt_BF52C14D657B9B571E38A26D0BDDF277" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PayablesToBrokerDealersAndClearingOrganizations" xlink:label="loc_us-gaap_PayablesToBrokerDealersAndClearingOrganizations_32A887A6D82E9EF1C386A26D0BDDB7C1" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_PayablesToBrokerDealersAndClearingOrganizations_32A887A6D82E9EF1C386A26D0BDDB7C1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_BD9759B713ACD25BF48CA26D0BDD1391" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_DerivativeLiabilities_BD9759B713ACD25BF48CA26D0BDD1391" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsPayableCurrentAndNoncurrent" xlink:label="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_10BCD000D1BEB6EE1447A26D0BDDEDAF" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_10BCD000D1BEB6EE1447A26D0BDDEDAF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_6ADBEAAF40762E04FF73A26D0BDD2C44" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_6ADBEAAF40762E04FF73A26D0BDD2C44" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_9823F1910826DA341642A26D0BDD8FFF" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_9823F1910826DA341642A26D0BDD8FFF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_C43821E940E96D88A158A26D0BDD5551" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_A829E3355DC7D9EACA38A26D0BDD00FD" xlink:to="loc_us-gaap_Liabilities_C43821E940E96D88A158A26D0BDD5551" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:to="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_D864B1366FF0188AE22CA26D0BDD4677" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_PreferredStockValue_D864B1366FF0188AE22CA26D0BDD4677" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PreferredStock7.750SeriesBValueIssued" xlink:label="loc_agnc_PreferredStock7.750SeriesBValueIssued_B6BB495F5A66CE66C002A26D0BDD474F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_agnc_PreferredStock7.750SeriesBValueIssued_B6BB495F5A66CE66C002A26D0BDD474F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_9CE5097FBC71708940FEA26D0BDD5C0D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_CommonStockValue_9CE5097FBC71708940FEA26D0BDD5C0D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_A329B2D4730CBC355410A26D0BDD055A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_AdditionalPaidInCapital_A329B2D4730CBC355410A26D0BDD055A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_76595DAEBEA2BDE72723A26D0BDD7C25" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_76595DAEBEA2BDE72723A26D0BDD7C25" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_62885EC536A15377B8E3A26D0BDD0A42" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_62885EC536A15377B8E3A26D0BDD0A42" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_946E68D19C202B3F9C1EA26D0BDDB2DC" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_B8DD6B158AEA859B937BA26D0BDD7902" xlink:to="loc_us-gaap_StockholdersEquity_946E68D19C202B3F9C1EA26D0BDDB2DC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_1A60E5FD87B11810A719A26D0BDD0350" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3A8D1FB40C22C438FA0AA26D0BDDD839" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_1A60E5FD87B11810A719A26D0BDD0350" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_DF2588DBCEBECE15888A5D161C3BC912" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_StatementTable_DF2588DBCEBECE15888A5D161C3BC912" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_C2EB80D925B187C6AEFE5D161C3BB71D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_DF2588DBCEBECE15888A5D161C3BC912" xlink:to="loc_us-gaap_StatementScenarioAxis_C2EB80D925B187C6AEFE5D161C3BB71D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_2332D0D57888B0272CF85D161C3B5CC8_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_C2EB80D925B187C6AEFE5D161C3BB71D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_2332D0D57888B0272CF85D161C3B5CC8_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_2332D0D57888B0272CF85D161C3B5CC8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_C2EB80D925B187C6AEFE5D161C3BB71D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_2332D0D57888B0272CF85D161C3B5CC8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_A2C6C63FAB0A87A9F1945D161C3BC0BF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_DF2588DBCEBECE15888A5D161C3BC912" xlink:to="loc_us-gaap_StatementClassOfStockAxis_A2C6C63FAB0A87A9F1945D161C3BC0BF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_8CF89F7F9ED377C5D6EC5D161C3BD782_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_A2C6C63FAB0A87A9F1945D161C3BC0BF" xlink:to="loc_us-gaap_ClassOfStockDomain_8CF89F7F9ED377C5D6EC5D161C3BD782_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_8CF89F7F9ED377C5D6EC5D161C3BD782" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_A2C6C63FAB0A87A9F1945D161C3BC0BF" xlink:to="loc_us-gaap_ClassOfStockDomain_8CF89F7F9ED377C5D6EC5D161C3BD782" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_0BCA37551C8DE67CFF345D161C3BC3F0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_0BCA37551C8DE67CFF345D161C3BC3F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecuritiesPledgedAsCollateral" xlink:label="loc_us-gaap_TradingSecuritiesPledgedAsCollateral_9C0E8220F13666060D9B5D161C3B73BE" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_TradingSecuritiesPledgedAsCollateral_9C0E8220F13666060D9B5D161C3B73BE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AssetsPledgedIncludedInReceivableForSecuritiesSold" xlink:label="loc_agnc_AssetsPledgedIncludedInReceivableForSecuritiesSold_2B7CC57A9CE0F6952B005D161C3BFA8B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_agnc_AssetsPledgedIncludedInReceivableForSecuritiesSold_2B7CC57A9CE0F6952B005D161C3BFA8B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_181FB9FD8CA8E95B2E975D161C3BC054" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_181FB9FD8CA8E95B2E975D161C3BC054" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_D0E6FEEBD5608EC946055D161C3B8F96" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_D0E6FEEBD5608EC946055D161C3B8F96" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued_929B0E3DCE96FF61332C5D161C3BD4D9" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_PreferredStockSharesIssued_929B0E3DCE96FF61332C5D161C3BD4D9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_6AD0B1EE57C7F04861115D161C4AF57F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_6AD0B1EE57C7F04861115D161C4AF57F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PrefdStockLiquidationPreference" xlink:label="loc_agnc_PrefdStockLiquidationPreference_C474083D4DA2BA80A2D95D161C4A1F85" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_agnc_PrefdStockLiquidationPreference_C474083D4DA2BA80A2D95D161C4A1F85" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_3EAD67B2EBCE71D1E7F45D161C4AADA3" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_3EAD67B2EBCE71D1E7F45D161C4AADA3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_F848B55162A52167C2AB5D161C4ACDF6" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_F848B55162A52167C2AB5D161C4ACDF6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_3861E7A2516077464D465D161C4AC8C4" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_CommonStockSharesIssued_3861E7A2516077464D465D161C4AC8C4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_ABBCED52D77CF11F44255D161C4AF63C" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C733E486ABC7CAF63F5A5D161C3B7155" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_ABBCED52D77CF11F44255D161C4AF63C" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/ConsolidatedStatementOfStockholdersEquity" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_D5187DDE0D22B723D745ACA19F4E1404" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StatementTable_D5187DDE0D22B723D745ACA19F4E1404" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_BBE1FFD0E15A25D24922ACA19F4EAFAA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_D5187DDE0D22B723D745ACA19F4E1404" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_BBE1FFD0E15A25D24922ACA19F4EAFAA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7EDBEF97D4DF256D5015ACA19F4E12CC_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_BBE1FFD0E15A25D24922ACA19F4EAFAA" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7EDBEF97D4DF256D5015ACA19F4E12CC_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7EDBEF97D4DF256D5015ACA19F4E12CC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_BBE1FFD0E15A25D24922ACA19F4EAFAA" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7EDBEF97D4DF256D5015ACA19F4E12CC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_49AB9D0B283F47E317CCACA19F4EE5B0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7EDBEF97D4DF256D5015ACA19F4E12CC" xlink:to="loc_us-gaap_InterestRateSwapMember_49AB9D0B283F47E317CCACA19F4EE5B0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_003F105FC4C0243662D2ACA19F4E2F33" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_D5187DDE0D22B723D745ACA19F4E1404" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_003F105FC4C0243662D2ACA19F4E2F33" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_003F105FC4C0243662D2ACA19F4E2F33" xlink:to="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_003F105FC4C0243662D2ACA19F4E2F33" xlink:to="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockMember" xlink:label="loc_us-gaap_PreferredStockMember_3EE78E7BDF47E8DF6DC1ACA19F4ECDF2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:to="loc_us-gaap_PreferredStockMember_3EE78E7BDF47E8DF6DC1ACA19F4ECDF2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_5193242FB3E34F2DD3ACACA19F4FF926" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:to="loc_us-gaap_CommonStockMember_5193242FB3E34F2DD3ACACA19F4FF926" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_4E2DE8A6C5CAC0709DB0ACA19F4F63FA" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_4E2DE8A6C5CAC0709DB0ACA19F4F63FA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_3633F9BD9BCD2B424730ACA19F4F6C59" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:to="loc_us-gaap_RetainedEarningsMember_3633F9BD9BCD2B424730ACA19F4F6C59" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_884F81CA8F1760DFDEB4ACA19F4F2D9D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_58C11B4526EE8DEA4206ACA19F4EEB77" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_884F81CA8F1760DFDEB4ACA19F4F2D9D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_03065E406DCB4C17B514ACA19F4FFD5E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StockholdersEquity_03065E406DCB4C17B514ACA19F4FFD5E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_DA37047A1C08150E9A41ACA19F4FF196" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_DA37047A1C08150E9A41ACA19F4FF196" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_BA70E4A12EB64CF36864ACA19F4FC04E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_BA70E4A12EB64CF36864ACA19F4FC04E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_16BBCFBB8017D7E98519ACA19F4FBC82" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_NetIncomeLoss_16BBCFBB8017D7E98519ACA19F4FBC82" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_B2F5E19EFC613CAA2EB1ACA19F4F317D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_B2F5E19EFC613CAA2EB1ACA19F4F317D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_9E593CA3F07F0B5E1861ACA19F4FCA79" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_B2F5E19EFC613CAA2EB1ACA19F4F317D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_9E593CA3F07F0B5E1861ACA19F4FCA79" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_004879EBBFED7D04FCBAACA19F4F0E1A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_B2F5E19EFC613CAA2EB1ACA19F4F317D" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_004879EBBFED7D04FCBAACA19F4F0E1A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredUnitsIssued" xlink:label="loc_us-gaap_PreferredUnitsIssued_8A98EE4277FD3C073823ACA19F4FF905" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_PreferredUnitsIssued_8A98EE4277FD3C073823ACA19F4FF905" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_BA89FE7A293B8D9D5740ACA19F4F95F7" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_BA89FE7A293B8D9D5740ACA19F4F95F7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_979E94CCB25DE4CB7104ACA19F4FD7F2" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_979E94CCB25DE4CB7104ACA19F4FD7F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_24A0CC9975BCA2CFCFAFACA19F4FA7E5" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_24A0CC9975BCA2CFCFAFACA19F4FA7E5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsPreferredStockCash" xlink:label="loc_us-gaap_DividendsPreferredStockCash_A6A9A9546B9EC2104A42ACA19F4F2D66" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_DividendsPreferredStockCash_A6A9A9546B9EC2104A42ACA19F4F2D66" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_730B252DC905087B6C8CACA19F4F19B1" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_730B252DC905087B6C8CACA19F4F19B1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_DEF202DFF73FAEE03CB2ACA19F4FEFEA" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_DEF202DFF73FAEE03CB2ACA19F4FEFEA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_3A1B06D3F5EA11721786ACA19F501618" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B2A5CB31220F8B3C1C95ACA19F4F69C3" xlink:to="loc_us-gaap_DividendsCommonStockCash_3A1B06D3F5EA11721786ACA19F501618" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_45CD0D84B2B59B9F941FA2BCC5F0ABB8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_StatementTable_45CD0D84B2B59B9F941FA2BCC5F0ABB8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_16F45C14AF775BAA15DDA2BCC5F03CB6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_45CD0D84B2B59B9F941FA2BCC5F0ABB8" xlink:to="loc_us-gaap_StatementScenarioAxis_16F45C14AF775BAA15DDA2BCC5F03CB6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_A027D322828E840D75DDA2BCC5F0A9AE_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_16F45C14AF775BAA15DDA2BCC5F03CB6" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_A027D322828E840D75DDA2BCC5F0A9AE_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_A027D322828E840D75DDA2BCC5F0A9AE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_16F45C14AF775BAA15DDA2BCC5F03CB6" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_A027D322828E840D75DDA2BCC5F0A9AE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestIncomeExpenseNetAbstract" xlink:label="loc_us-gaap_InterestIncomeExpenseNetAbstract_438793E784B8C5B6EAD0A2BCC5F08D38" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_InterestIncomeExpenseNetAbstract_438793E784B8C5B6EAD0A2BCC5F08D38" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestIncomeSecuritiesMortgageBacked" xlink:label="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_3B86CD5A2887D027C26EA2BCC5F054CA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestIncomeExpenseNetAbstract_438793E784B8C5B6EAD0A2BCC5F08D38" xlink:to="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_3B86CD5A2887D027C26EA2BCC5F054CA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_63580C43AAF12ABC360FA2BCC5F17D09" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestIncomeExpenseNetAbstract_438793E784B8C5B6EAD0A2BCC5F08D38" xlink:to="loc_us-gaap_InterestExpense_63580C43AAF12ABC360FA2BCC5F17D09" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_2389F305A2D1D3FEAE8CA2BCC5F18E85" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestIncomeExpenseNetAbstract_438793E784B8C5B6EAD0A2BCC5F08D38" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_2389F305A2D1D3FEAE8CA2BCC5F18E85" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoninterestIncomeAbstract" xlink:label="loc_us-gaap_NoninterestIncomeAbstract_BCEBDC8BD94792CDE633A2BCC5F14A15" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_NoninterestIncomeAbstract_BCEBDC8BD94792CDE633A2BCC5F14A15" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS" xlink:label="loc_us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS_D97FC3E817A9B1BF2A31A2BCC5F147F4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_BCEBDC8BD94792CDE633A2BCC5F14A15" xlink:to="loc_us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS_D97FC3E817A9B1BF2A31A2BCC5F147F4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_Gainlossonderivativeinstrumentsandothersecuritiesnet" xlink:label="loc_agnc_Gainlossonderivativeinstrumentsandothersecuritiesnet_B485B57AF810F1517AC4A2BCC5F1296F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_BCEBDC8BD94792CDE633A2BCC5F14A15" xlink:to="loc_agnc_Gainlossonderivativeinstrumentsandothersecuritiesnet_B485B57AF810F1517AC4A2BCC5F1296F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoninterestIncome" xlink:label="loc_us-gaap_NoninterestIncome_F548F161C9D36E03EAB4A2BCC5F216F2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_BCEBDC8BD94792CDE633A2BCC5F14A15" xlink:to="loc_us-gaap_NoninterestIncome_F548F161C9D36E03EAB4A2BCC5F216F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoninterestExpenseAbstract" xlink:label="loc_us-gaap_NoninterestExpenseAbstract_02C5860DAC7A4CD485D0A2BCC5F2BACB" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_NoninterestExpenseAbstract_02C5860DAC7A4CD485D0A2BCC5F2BACB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ManagementFeeExpense" xlink:label="loc_us-gaap_ManagementFeeExpense_F4D6E6930859BF59B4FCA2BCC5F264C5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_02C5860DAC7A4CD485D0A2BCC5F2BACB" xlink:to="loc_us-gaap_ManagementFeeExpense_F4D6E6930859BF59B4FCA2BCC5F264C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_DCE1F28A9DE27CE16BB7A2BCC5F25471" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_02C5860DAC7A4CD485D0A2BCC5F2BACB" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_DCE1F28A9DE27CE16BB7A2BCC5F25471" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_04D1B5AA3DB92C2C78ECA2BCC5F256D9" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_02C5860DAC7A4CD485D0A2BCC5F2BACB" xlink:to="loc_us-gaap_OperatingExpenses_04D1B5AA3DB92C2C78ECA2BCC5F256D9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_81463F9D84B1295D8580A2BCC5F22A56" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_81463F9D84B1295D8580A2BCC5F22A56" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ExciseAndReitIncomeTax" xlink:label="loc_agnc_ExciseAndReitIncomeTax_EBC210E3008AC417B93AA2BCC5F25D24" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_agnc_ExciseAndReitIncomeTax_EBC210E3008AC417B93AA2BCC5F25D24" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_7B5FE5BB53025DF689DEA2BCC5F26DA0" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_7B5FE5BB53025DF689DEA2BCC5F26DA0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_D67F419BEE40A12C2D0AA2BCC5F2F98E" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_NetIncomeLoss_D67F419BEE40A12C2D0AA2BCC5F2F98E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_000A3598D45F719FEB22A2BCC5F2CD02" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_000A3598D45F719FEB22A2BCC5F2CD02" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_C17DFF6A18F3DCBA31DCA2BCC5F3FCFF" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_C17DFF6A18F3DCBA31DCA2BCC5F3FCFF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_A66306B6662B7D142072A2BCC5F380F2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_C17DFF6A18F3DCBA31DCA2BCC5F3FCFF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_A66306B6662B7D142072A2BCC5F380F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_F0340F3438A02C14BD75A2BCC5F3F610" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_C17DFF6A18F3DCBA31DCA2BCC5F3FCFF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_F0340F3438A02C14BD75A2BCC5F3F610" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_F545221C410537A6BC84A2BCC5F3E6DB" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_C17DFF6A18F3DCBA31DCA2BCC5F3FCFF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_F545221C410537A6BC84A2BCC5F3E6DB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_5E3DC8D74C13AB6FC17DA2BCC5F3F0C5" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_5E3DC8D74C13AB6FC17DA2BCC5F3F0C5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ComprehensiveIncomeAvailableToCommonShareholders" xlink:label="loc_agnc_ComprehensiveIncomeAvailableToCommonShareholders_1437118E2BCC8261B3B6A2BCC5F48621" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_agnc_ComprehensiveIncomeAvailableToCommonShareholders_1437118E2BCC8261B3B6A2BCC5F48621" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_1F5DA0C52253DB3A9C5BA2BCC5F4DF5E" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_1F5DA0C52253DB3A9C5BA2BCC5F4DF5E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="loc_us-gaap_EarningsPerShareBasicAndDiluted_A03E46E06C01EAE17363A2BCC5F4CB7B" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_EarningsPerShareBasicAndDiluted_A03E46E06C01EAE17363A2BCC5F4CB7B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ComprehensiveIncomePerShareBasicAndDiluted" xlink:label="loc_agnc_ComprehensiveIncomePerShareBasicAndDiluted_82ABBC8D2EE9F696E849A2BCC5F4257F" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_agnc_ComprehensiveIncomePerShareBasicAndDiluted_82ABBC8D2EE9F696E849A2BCC5F4257F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_964CDDDA03EB0C82A576A2BCC5F407C2" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F67D714A0929FA29F025A2BCC5F0153C" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_964CDDDA03EB0C82A576A2BCC5F407C2" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstruments" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfDerivativeInstrumentsNotDesignatedAsHedgesOnIncomeStatementDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_27D4BD34D0A350552036F0C8A5D6F40A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_DerivativeTable_27D4BD34D0A350552036F0C8A5D6F40A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_9D568C01862C055DF224F0C8A5D6E3F9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_27D4BD34D0A350552036F0C8A5D6F40A" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_9D568C01862C055DF224F0C8A5D6E3F9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_BA7DAA24435F2DB5BDABF0C8A5D6F60A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_9D568C01862C055DF224F0C8A5D6E3F9" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_BA7DAA24435F2DB5BDABF0C8A5D6F60A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_BA7DAA24435F2DB5BDABF0C8A5D6F60A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_9D568C01862C055DF224F0C8A5D6E3F9" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_BA7DAA24435F2DB5BDABF0C8A5D6F60A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_72A492B4F5B26B4BB104F0C8A5D6CE98" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_BA7DAA24435F2DB5BDABF0C8A5D6F60A" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_72A492B4F5B26B4BB104F0C8A5D6CE98" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_D234A0991708A47AE9FFF0C8A5D69184" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_27D4BD34D0A350552036F0C8A5D6F40A" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_D234A0991708A47AE9FFF0C8A5D69184" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_D234A0991708A47AE9FFF0C8A5D69184" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_D234A0991708A47AE9FFF0C8A5D69184" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_7B71D052A881C6C98A33F0C8A5D67CE1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_7B71D052A881C6C98A33F0C8A5D67CE1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_1605BEB68AB49C042C64F0C8A5D65F34" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_us-gaap_InterestRateSwapMember_1605BEB68AB49C042C64F0C8A5D65F34" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_AB4758F864228E889FA9F0C8A5D6A1BF" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_AB4758F864228E889FA9F0C8A5D6A1BF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_3C6A79CFF95E0577418EF0C8A5D6DBBF" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_3C6A79CFF95E0577418EF0C8A5D6DBBF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_54F7C6071240E90CC19FF0C8A5D6D3EF" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_us-gaap_PutOptionMember_54F7C6071240E90CC19FF0C8A5D6D3EF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsMember" xlink:label="loc_agnc_InterestRateSwapsMember_31D610F7F52CDACDBDBCF0C8A5D6A357" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_InterestRateSwapsMember_31D610F7F52CDACDBDBCF0C8A5D6A357" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverInterestRateSwapsMember" xlink:label="loc_agnc_ReceiverInterestRateSwapsMember_605BE719CEBE3BD32D34F0C8A5D7A318" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_ReceiverInterestRateSwapsMember_605BE719CEBE3BD32D34F0C8A5D7A318" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_47C2252473346D695157F0C8A5D7F74F" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_PayerSwaptionMember_47C2252473346D695157F0C8A5D7F74F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_22177D1676946426AB1EF0C8A5D7C2F2" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_ReceiverSwaptionMember_22177D1676946426AB1EF0C8A5D7C2F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_5F5DD7E044CCAB925627F0C8A5D7CC04" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_5F5DD7E044CCAB925627F0C8A5D7CC04" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_MarkitIosTotalReturnSwapsLongMember" xlink:label="loc_agnc_MarkitIosTotalReturnSwapsLongMember_5511A569DDC45221292BF0C8A5D75E14" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_MarkitIosTotalReturnSwapsLongMember_5511A569DDC45221292BF0C8A5D75E14" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_MarkitIosTotalReturnSwapsShortMember" xlink:label="loc_agnc_MarkitIosTotalReturnSwapsShortMember_B7DA0B5E4A08E6EB3AF5F0C8A5D7B4E4" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C2CCBAA82D44CFAD2324F0C8A5D605BD" xlink:to="loc_agnc_MarkitIosTotalReturnSwapsShortMember_B7DA0B5E4A08E6EB3AF5F0C8A5D7B4E4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_C7E6433D0C803CFA98F5F0C8A5D7DFC7" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_27D4BD34D0A350552036F0C8A5D6F40A" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_C7E6433D0C803CFA98F5F0C8A5D7DFC7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_E3DDA6D39D07E10088FEF0C8A5D78A96_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_C7E6433D0C803CFA98F5F0C8A5D7DFC7" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_E3DDA6D39D07E10088FEF0C8A5D78A96_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_E3DDA6D39D07E10088FEF0C8A5D78A96" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_C7E6433D0C803CFA98F5F0C8A5D7DFC7" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_E3DDA6D39D07E10088FEF0C8A5D78A96" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_0B41164622F0F7D4A667F0C8A5D72620" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_E3DDA6D39D07E10088FEF0C8A5D78A96" xlink:to="loc_us-gaap_PutOptionMember_0B41164622F0F7D4A667F0C8A5D72620" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainLossOnSecurities" xlink:label="loc_us-gaap_UnrealizedGainLossOnSecurities_5BAEB0A2F1870ACADAB1F0C8A5D7DBEE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_UnrealizedGainLossOnSecurities_5BAEB0A2F1870ACADAB1F0C8A5D7DBEE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_929E16641B4D2493F309F0C8A5D7190C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_929E16641B4D2493F309F0C8A5D7190C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_6C6748A9FBD89EDD8114F0C8A5D78187" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_6C6748A9FBD89EDD8114F0C8A5D78187" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherRealizedGainLossOnDerivativeInstrumentsAndOtherSecuritiesNet" xlink:label="loc_agnc_OtherRealizedGainLossOnDerivativeInstrumentsAndOtherSecuritiesNet_F6672E1C061658B7151CF0C8A5D7E608" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_agnc_OtherRealizedGainLossOnDerivativeInstrumentsAndOtherSecuritiesNet_F6672E1C061658B7151CF0C8A5D7E608" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_BE63DAAA621FBF58F413F0C8A5D7FF77" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_BE63DAAA621FBF58F413F0C8A5D7FF77" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_B008EED0A8D7E36FD16DF0C8A5D79758" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_B008EED0A8D7E36FD16DF0C8A5D79758" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_454456B0C446171B48E7F0C8A5D7216F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_454456B0C446171B48E7F0C8A5D7216F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_1F7B965EAB6B4393AE5CF0C8A5D8C9C5" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_1F7B965EAB6B4393AE5CF0C8A5D8C9C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_C8C4CE0DF96583BBFA10F0C8A5D8A0C2" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_C8C4CE0DF96583BBFA10F0C8A5D8A0C2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecurities" xlink:label="loc_us-gaap_TradingSecurities_5FBE5B6DC0EDB91E2039F0C8A5D8AEB2" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_TradingSecurities_5FBE5B6DC0EDB91E2039F0C8A5D8AEB2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeNetHedgeIneffectivenessGainLoss" xlink:label="loc_us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_C780CC3EB9532E3EF799F0C8A5D8DD6D" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E38279EFAF2C34423C69F0C8A5D731B0" xlink:to="loc_us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_C780CC3EB9532E3EF799F0C8A5D8DD6D" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfForwardContractsDesignatedAsHedgesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_E0EE160D101491052B66F0C8A4B085B9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_DerivativeTable_E0EE160D101491052B66F0C8A4B085B9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_F30639840B92C6088D90F0C8A4B0527D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E0EE160D101491052B66F0C8A4B085B9" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_F30639840B92C6088D90F0C8A4B0527D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_EC4464DCAF19A3C49A50F0C8A4B0EC91_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_F30639840B92C6088D90F0C8A4B0527D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_EC4464DCAF19A3C49A50F0C8A4B0EC91_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_EC4464DCAF19A3C49A50F0C8A4B0EC91" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_F30639840B92C6088D90F0C8A4B0527D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_EC4464DCAF19A3C49A50F0C8A4B0EC91" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_27060FDAD59CCF467973F0C8A4B00002" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_EC4464DCAF19A3C49A50F0C8A4B0EC91" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_27060FDAD59CCF467973F0C8A4B00002" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_801D3E9F19E93AA2225EF0C8A4B094E3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_801D3E9F19E93AA2225EF0C8A4B094E3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_E5C7B5DDDF9C92FFA62CF0C8A4B068A1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_E5C7B5DDDF9C92FFA62CF0C8A4B068A1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_A94C814DF079A4CD3539F0C8A4B0217A" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_A94C814DF079A4CD3539F0C8A4B0217A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_FD0E26D0736BFA7CB066F0C8A4B16EB8" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_FD0E26D0736BFA7CB066F0C8A4B16EB8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_CA10A7010452066B3079F0C8A4B19BF3" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4D8710534BBE443947FAF0C8A4B09544" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_CA10A7010452066B3079F0C8A4B19BF3" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsEffectOfInterestRateSwapsDesignatedAsHedgesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_B123ADED2D2BB7A5D4C3F0C8A54C4E02" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_B123ADED2D2BB7A5D4C3F0C8A54C4E02" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_74D7D137A06BC41D4FAAF0C8A54C353F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_B123ADED2D2BB7A5D4C3F0C8A54C4E02" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_74D7D137A06BC41D4FAAF0C8A54C353F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_74D7D137A06BC41D4FAAF0C8A54C353F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_B123ADED2D2BB7A5D4C3F0C8A54C4E02" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_74D7D137A06BC41D4FAAF0C8A54C353F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_0944A36F63A75CBC1153F0C8A54C42DF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_74D7D137A06BC41D4FAAF0C8A54C353F" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_0944A36F63A75CBC1153F0C8A54C42DF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_E364C535D757A5D4410AF0C8A54C2C92" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_E364C535D757A5D4410AF0C8A54C2C92" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_F4E11B6B5B25BBE59D81F0C8A54C01D8_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_E364C535D757A5D4410AF0C8A54C2C92" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_F4E11B6B5B25BBE59D81F0C8A54C01D8_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_F4E11B6B5B25BBE59D81F0C8A54C01D8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_E364C535D757A5D4410AF0C8A54C2C92" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_F4E11B6B5B25BBE59D81F0C8A54C01D8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_35B310BC03700EF769DDF0C8A54C7AB6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_F4E11B6B5B25BBE59D81F0C8A54C01D8" xlink:to="loc_us-gaap_InterestRateSwapMember_35B310BC03700EF769DDF0C8A54C7AB6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_A26EA8B86810454FD94DF0C8A54CDF33" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:to="loc_us-gaap_HedgingDesignationAxis_A26EA8B86810454FD94DF0C8A54CDF33" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_767C7ABE173CE0A4DC30F0C8A54C1E39_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_A26EA8B86810454FD94DF0C8A54CDF33" xlink:to="loc_us-gaap_HedgingDesignationDomain_767C7ABE173CE0A4DC30F0C8A54C1E39_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_767C7ABE173CE0A4DC30F0C8A54C1E39" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_A26EA8B86810454FD94DF0C8A54CDF33" xlink:to="loc_us-gaap_HedgingDesignationDomain_767C7ABE173CE0A4DC30F0C8A54C1E39" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_A4081A1948F7B2DD0665F0C8A54C9D23" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_239988838F2DDCDD2771F0C8A54C85B7" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_A4081A1948F7B2DD0665F0C8A54C9D23" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9B7259F4FF6EEECBE076F0C8A54CED2F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_A4081A1948F7B2DD0665F0C8A54C9D23" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9B7259F4FF6EEECBE076F0C8A54CED2F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9B7259F4FF6EEECBE076F0C8A54CED2F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_A4081A1948F7B2DD0665F0C8A54C9D23" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9B7259F4FF6EEECBE076F0C8A54CED2F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_9ABE6059372C09E7AB6FF0C8A54D268D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_9ABE6059372C09E7AB6FF0C8A54D268D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetPeriodicInterestRateCostsOnSwaps" xlink:label="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_D4534F0E5113A3C1B7E6F0C8A54D2AA5" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_D4534F0E5113A3C1B7E6F0C8A54D2AA5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_98CDC844FA78118A33D7F0C8A54D78A7" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_98CDC844FA78118A33D7F0C8A54D78A7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_99D0845FCB0A743A4710F0C8A54DB2A4" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_99D0845FCB0A743A4710F0C8A54DB2A4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_C59D6D8C1643F59D7587F0C8A54D8EC3" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_C59D6D8C1643F59D7587F0C8A54D8EC3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion" xlink:label="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_A658B07AE076C2288B7BF0C8A54D6EEB" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2338D6A5F890544D74ABF0C8A54C4AE3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_A658B07AE076C2288B7BF0C8A54D6EEB" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsNarrativeDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_011BE16465712F1EAA58B0A3E2C2F44E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_DerivativeByNatureAxis_011BE16465712F1EAA58B0A3E2C2F44E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_71A3E40223202FB59FC5B0A3E2C23D56_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_011BE16465712F1EAA58B0A3E2C2F44E" xlink:to="loc_agnc_DerivativebyNatureDomain_71A3E40223202FB59FC5B0A3E2C23D56_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_71A3E40223202FB59FC5B0A3E2C23D56" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_011BE16465712F1EAA58B0A3E2C2F44E" xlink:to="loc_agnc_DerivativebyNatureDomain_71A3E40223202FB59FC5B0A3E2C23D56" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_EE4EE3891ECDBA9DCEA7B0A3E2C208AF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_71A3E40223202FB59FC5B0A3E2C23D56" xlink:to="loc_us-gaap_ForwardContractsMember_EE4EE3891ECDBA9DCEA7B0A3E2C208AF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_CB9DF6AE7175D7E9702BB0A3E2C2A27E" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_CB9DF6AE7175D7E9702BB0A3E2C2A27E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B2DEAE0CEBC33027DF17B0A3E2C20F41_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_CB9DF6AE7175D7E9702BB0A3E2C2A27E" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B2DEAE0CEBC33027DF17B0A3E2C20F41_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B2DEAE0CEBC33027DF17B0A3E2C20F41" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_CB9DF6AE7175D7E9702BB0A3E2C2A27E" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B2DEAE0CEBC33027DF17B0A3E2C20F41" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TBAandForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_E27670BB56EF4779B7B2B0A3E2C20EDB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B2DEAE0CEBC33027DF17B0A3E2C20F41" xlink:to="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_E27670BB56EF4779B7B2B0A3E2C20EDB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02B4E7E7866E6C2D5E43B0A3E2C2A9FA" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02B4E7E7866E6C2D5E43B0A3E2C2A9FA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_75E84E1806A8B856942FB0A3E2C2C5EA_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02B4E7E7866E6C2D5E43B0A3E2C2A9FA" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_75E84E1806A8B856942FB0A3E2C2C5EA_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_75E84E1806A8B856942FB0A3E2C2C5EA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02B4E7E7866E6C2D5E43B0A3E2C2A9FA" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_75E84E1806A8B856942FB0A3E2C2C5EA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_00BAD4AB9D8051EE3397B0A3E2C2F818" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_75E84E1806A8B856942FB0A3E2C2C5EA" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_00BAD4AB9D8051EE3397B0A3E2C2F818" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_8E4341D777C90163FEA2B0A3E2C2A876" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_8E4341D777C90163FEA2B0A3E2C2A876" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_A9A5F0508CB433B6E754B0A3E2C20A4F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_8E4341D777C90163FEA2B0A3E2C2A876" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_A9A5F0508CB433B6E754B0A3E2C20A4F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_A9A5F0508CB433B6E754B0A3E2C20A4F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_8E4341D777C90163FEA2B0A3E2C2A876" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_A9A5F0508CB433B6E754B0A3E2C20A4F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_1DBC596428147A541ADAB0A3E2C22E30" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_A9A5F0508CB433B6E754B0A3E2C20A4F" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_1DBC596428147A541ADAB0A3E2C22E30" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionAxis" xlink:label="loc_agnc_DerivativePositionAxis_A8B94BA8BF7B88B05C15B0A3E2C2ED47" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_agnc_DerivativePositionAxis_A8B94BA8BF7B88B05C15B0A3E2C2ED47" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_2988E734958F6C8DAA88B0A3E2C28E7F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativePositionAxis_A8B94BA8BF7B88B05C15B0A3E2C2ED47" xlink:to="loc_agnc_DerivativePositionDomain_2988E734958F6C8DAA88B0A3E2C28E7F_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_2988E734958F6C8DAA88B0A3E2C28E7F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativePositionAxis_A8B94BA8BF7B88B05C15B0A3E2C2ED47" xlink:to="loc_agnc_DerivativePositionDomain_2988E734958F6C8DAA88B0A3E2C28E7F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_535849736B087F1B5108B0A3E2C2D51C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativePositionDomain_2988E734958F6C8DAA88B0A3E2C28E7F" xlink:to="loc_us-gaap_InterestRateSwapMember_535849736B087F1B5108B0A3E2C2D51C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_62F0CF8F61799091FD31B0A3E2C22D96" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_InvestmentTypeAxis_62F0CF8F61799091FD31B0A3E2C22D96" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_9C0DE42DDFD0C9012B7CB0A3E2C22A97_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_62F0CF8F61799091FD31B0A3E2C22D96" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_9C0DE42DDFD0C9012B7CB0A3E2C22A97_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_9C0DE42DDFD0C9012B7CB0A3E2C22A97" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_62F0CF8F61799091FD31B0A3E2C22D96" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_9C0DE42DDFD0C9012B7CB0A3E2C22A97" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TotalReturnSwapMember" xlink:label="loc_us-gaap_TotalReturnSwapMember_3DCD05B1FF7AE234BCC3B0A3E2C2CD89" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_9C0DE42DDFD0C9012B7CB0A3E2C22A97" xlink:to="loc_us-gaap_TotalReturnSwapMember_3DCD05B1FF7AE234BCC3B0A3E2C2CD89" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_47F875CE9481FD36C4E1B0A3E2C23EF5" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_47F875CE9481FD36C4E1B0A3E2C23EF5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_6B00B1EE6DC7144345E2B0A3E2C27162_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_47F875CE9481FD36C4E1B0A3E2C23EF5" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_6B00B1EE6DC7144345E2B0A3E2C27162_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_6B00B1EE6DC7144345E2B0A3E2C27162" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_47F875CE9481FD36C4E1B0A3E2C23EF5" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_6B00B1EE6DC7144345E2B0A3E2C27162" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_8B17D486B3F29DE9C475B0A3E2C2F777" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_6B00B1EE6DC7144345E2B0A3E2C27162" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_8B17D486B3F29DE9C475B0A3E2C2F777" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_C6CC9C41D762E0916B55B0A3E2C2CA8E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4E1DB011EB1774A6DBBFB0A3E2C21ED6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_C6CC9C41D762E0916B55B0A3E2C2CA8E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C6CC9C41D762E0916B55B0A3E2C2CA8E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C6CC9C41D762E0916B55B0A3E2C2CA8E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_0559961EA307F849B36DB0A3E2C24A38" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_0559961EA307F849B36DB0A3E2C24A38" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_B1863E61DD53FAAEC33BB0A3E2C27FE4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:to="loc_us-gaap_InterestRateSwapMember_B1863E61DD53FAAEC33BB0A3E2C27FE4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsMember" xlink:label="loc_agnc_InterestRateSwapsMember_19456076F1A11A00604DB0A3E2C205F2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:to="loc_agnc_InterestRateSwapsMember_19456076F1A11A00604DB0A3E2C205F2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_2FAEF0BA13DE73DEEC9DB0A3E2C24A16" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_84357815A7004AC9CC1BB0A3E2C21DE3" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_2FAEF0BA13DE73DEEC9DB0A3E2C24A16" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainlossonREITEquitySecurities" xlink:label="loc_agnc_GainlossonREITEquitySecurities_3A66EEC707859ACC4C18B0A3E2C2145B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_GainlossonREITEquitySecurities_3A66EEC707859ACC4C18B0A3E2C2145B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_6902CA2B469D956F8FBFB0A3E2C21B9A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeAssets_6902CA2B469D956F8FBFB0A3E2C21B9A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion" xlink:label="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_1CEA99E49237A936F6D4B0A3E2C2D07B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_1CEA99E49237A936F6D4B0A3E2C2D07B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_7B8C42D95F1250163AA1B0A3E2C24A29" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_7B8C42D95F1250163AA1B0A3E2C24A29" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetPeriodicInterestRateCostsOnSwaps" xlink:label="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_BD26C5FCDC576107F966B0A3E2C20261" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_BD26C5FCDC576107F966B0A3E2C20261" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_C4EC86379087BE423863B0A3E2C2BF67" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_C4EC86379087BE423863B0A3E2C2BF67" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge" xlink:label="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_5BCE74F096041F3FBA7AB0A3E2C254B7" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_5BCE74F096041F3FBA7AB0A3E2C254B7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_DE3CEC5471ACF19F125FB0A3E2C263C5" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_DE3CEC5471ACF19F125FB0A3E2C263C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_35F525BB5219A8DEB451B0A3E2C241B9" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_35F525BB5219A8DEB451B0A3E2C241B9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_533A54E95B770AB57822B0A3E2C2C520" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_533A54E95B770AB57822B0A3E2C2C520" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceivableUnderReverseRepurchaseAgreements" xlink:label="loc_agnc_ReceivableUnderReverseRepurchaseAgreements_9929CB4B9FC6742DEC22B0A3E2C22FBB" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_ReceivableUnderReverseRepurchaseAgreements_9929CB4B9FC6742DEC22B0A3E2C22FBB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell" xlink:label="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_372193367FF588647F25B0A3E2C2B0A3" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_372193367FF588647F25B0A3E2C2B0A3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths" xlink:label="loc_agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths_3AC9E267E708D94F3D87B0A3E2C2000A" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths_3AC9E267E708D94F3D87B0A3E2C2000A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_32FEE3C91AFAAEDA3CDAB0A3E2C2808C" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_32FEE3C91AFAAEDA3CDAB0A3E2C2808C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_08135FBE8104B73191C6B0A3E2C29128" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_08135FBE8104B73191C6B0A3E2C29128" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditDerivativeMaximumExposureUndiscounted" xlink:label="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_36FE660F12F503A3938EB0A3E2C25B9F" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_36FE660F12F503A3938EB0A3E2C25B9F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_FFFB347FA930730D774DB0A3E2C24635" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_FFFB347FA930730D774DB0A3E2C24635" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_2EC6DE9B8647B84CA9B5B0A3E2C2D702" xlink:type="locator" />
    <definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_FD7ED901E73C8CA139E5B0A3E2C25026" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_2EC6DE9B8647B84CA9B5B0A3E2C2D702" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsRemainingInterestRateSwapTermDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_4212ED75B6A7A5C814A9F0C8A4D33306" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeTable_4212ED75B6A7A5C814A9F0C8A4D33306" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionAxis" xlink:label="loc_agnc_DerivativePositionAxis_8599E52944BBB7D7BE96F0C8A4D3DB35" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4212ED75B6A7A5C814A9F0C8A4D33306" xlink:to="loc_agnc_DerivativePositionAxis_8599E52944BBB7D7BE96F0C8A4D3DB35" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_613A72FB419F706C0905F0C8A4D37FA4_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativePositionAxis_8599E52944BBB7D7BE96F0C8A4D3DB35" xlink:to="loc_agnc_DerivativePositionDomain_613A72FB419F706C0905F0C8A4D37FA4_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_613A72FB419F706C0905F0C8A4D37FA4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativePositionAxis_8599E52944BBB7D7BE96F0C8A4D3DB35" xlink:to="loc_agnc_DerivativePositionDomain_613A72FB419F706C0905F0C8A4D37FA4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_2156778915B0B6C84958F0C8A4D358E0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativePositionDomain_613A72FB419F706C0905F0C8A4D37FA4" xlink:to="loc_us-gaap_InterestRateSwapMember_2156778915B0B6C84958F0C8A4D358E0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityAxis" xlink:label="loc_agnc_DerivativesByMaturityAxis_4883531E8508D78571D4F0C8A4D36FDF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4212ED75B6A7A5C814A9F0C8A4D33306" xlink:to="loc_agnc_DerivativesByMaturityAxis_4883531E8508D78571D4F0C8A4D36FDF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_EE1DD86A6E4D9E34FEB6F0C8A4D4ADE7_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativesByMaturityAxis_4883531E8508D78571D4F0C8A4D36FDF" xlink:to="loc_agnc_DerivativesByMaturityDomain_EE1DD86A6E4D9E34FEB6F0C8A4D4ADE7_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_EE1DD86A6E4D9E34FEB6F0C8A4D4ADE7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativesByMaturityAxis_4883531E8508D78571D4F0C8A4D36FDF" xlink:to="loc_agnc_DerivativesByMaturityDomain_EE1DD86A6E4D9E34FEB6F0C8A4D4ADE7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_659E0917CE1C86803DF1F0C8A4D41A8F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_EE1DD86A6E4D9E34FEB6F0C8A4D4ADE7" xlink:to="loc_us-gaap_InterestRateSwapMember_659E0917CE1C86803DF1F0C8A4D41A8F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_A2095366C0DA6287579EF0C8A4D420DB" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4212ED75B6A7A5C814A9F0C8A4D33306" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_A2095366C0DA6287579EF0C8A4D420DB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_A2095366C0DA6287579EF0C8A4D420DB" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_A2095366C0DA6287579EF0C8A4D420DB" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_E0CD587882E5E3DD5247F0C8A4D4F705" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D" xlink:to="loc_us-gaap_InterestRateSwapMember_E0CD587882E5E3DD5247F0C8A4D4F705" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_233A38D84C2453E7F8DFF0C8A4D4CBED" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A32D47B12ECD56DEAC2CF0C8A4D4262D" xlink:to="loc_agnc_PayerSwaptionMember_233A38D84C2453E7F8DFF0C8A4D4CBED" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_FA6D6BA62A71D3AA766AF0C8A4D4A1BA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_FA6D6BA62A71D3AA766AF0C8A4D4A1BA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_FDAC05BB3FD29E5FA960F0C8A4D48BE9" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_FDAC05BB3FD29E5FA960F0C8A4D48BE9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_6E55BA7CB6DB684E30E2F0C8A4D41177" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_6E55BA7CB6DB684E30E2F0C8A4D41177" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_018CA057DF551E3578A8F0C8A4D41FC9" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_018CA057DF551E3578A8F0C8A4D41FC9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageVariableInterestRate" xlink:label="loc_us-gaap_DerivativeAverageVariableInterestRate_96BB8B2B6FC936072CF6F0C8A4D49B67" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeAverageVariableInterestRate_96BB8B2B6FC936072CF6F0C8A4D49B67" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet" xlink:label="loc_us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet_127CBC0035130C92FFAFF0C8A4D4A7E1" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet_127CBC0035130C92FFAFF0C8A4D4A7E1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_C7FE34CD21C673572571F0C8A4D426E8" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_invest_DerivativeNotionalAmount_C7FE34CD21C673572571F0C8A4D426E8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeHigherRemainingMaturityRange1" xlink:label="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_E45C24FC6A743A087DB6F0C8A4D45CF3" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_16F1E906023FB10783BCF0C8A4D48425" xlink:to="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_E45C24FC6A743A087DB6F0C8A4D45CF3" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfDerivativesOutstandingNotDesignatedAsHedgingInstrumentsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_A549DA25AB6EE1D1C1D492D56E47976C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_InvestmentTypeAxis_A549DA25AB6EE1D1C1D492D56E47976C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_80C600F7109820D805C892D56E485925_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_A549DA25AB6EE1D1C1D492D56E47976C" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_80C600F7109820D805C892D56E485925_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_80C600F7109820D805C892D56E485925" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_A549DA25AB6EE1D1C1D492D56E47976C" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_80C600F7109820D805C892D56E485925" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherDerivativesMember" xlink:label="loc_agnc_OtherDerivativesMember_3729535D5A9414B3297192D56E4D1E6F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_80C600F7109820D805C892D56E485925" xlink:to="loc_agnc_OtherDerivativesMember_3729535D5A9414B3297192D56E4D1E6F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_BE1DA5C77877DB68316C92D56E4D9415" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_DerivativeByNatureAxis_BE1DA5C77877DB68316C92D56E4D9415" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_BE1DA5C77877DB68316C92D56E4D9415" xlink:to="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_BE1DA5C77877DB68316C92D56E4D9415" xlink:to="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_447D9FED78D04E9F544292D56E4D59BE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_agnc_ReceiverSwaptionMember_447D9FED78D04E9F544292D56E4D59BE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_20D8AFA0540BDD59B0CE92D56E4DB6D9" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_agnc_PayerSwaptionMember_20D8AFA0540BDD59B0CE92D56E4DB6D9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_C1231D6EC63CF66F7A9692D56E4D5E7E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_NondesignatedMember_C1231D6EC63CF66F7A9692D56E4D5E7E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_F0962C15683B037008F392D56E4D3CE0" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_F0962C15683B037008F392D56E4D3CE0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_AB559D55541A87D2452192D56E4D551B" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_ForwardContractsMember_AB559D55541A87D2452192D56E4D551B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_E62E904AF7409AF99C3F92D56E4D55D1" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_ShortMember_E62E904AF7409AF99C3F92D56E4D55D1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_5B608DD83076095EDFA092D56E4D4DC2" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_LongMember_5B608DD83076095EDFA092D56E4D4DC2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_B9D4CD1512B472BCC33B92D56E4D1E56" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_476D41E264C78D51C9FE92D56E4D1004" xlink:to="loc_us-gaap_FutureMember_B9D4CD1512B472BCC33B92D56E4D1E56" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityAxis" xlink:label="loc_agnc_DerivativesByMaturityAxis_4EC01933DA455B95254892D56E4D0126" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_agnc_DerivativesByMaturityAxis_4EC01933DA455B95254892D56E4D0126" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativesByMaturityAxis_4EC01933DA455B95254892D56E4D0126" xlink:to="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativesByMaturityAxis_4EC01933DA455B95254892D56E4D0126" xlink:to="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LessThanOrEqualToOneYearMember" xlink:label="loc_agnc_LessThanOrEqualToOneYearMember_1BDD3FFD6FF22A72D16292D56E4D38D4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:to="loc_agnc_LessThanOrEqualToOneYearMember_1BDD3FFD6FF22A72D16292D56E4D38D4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_6198BCF897F8189FC96592D56E4D6623" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:to="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_6198BCF897F8189FC96592D56E4D6623" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember_B9E643A53FFB7FEBCF7992D56E4D3CD0" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:to="loc_agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember_B9E643A53FFB7FEBCF7992D56E4D3CD0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember" xlink:label="loc_agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember_6B278B4F8ABFB1F992E192D56E4D77C6" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:to="loc_agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember_6B278B4F8ABFB1F992E192D56E4D77C6" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember" xlink:label="loc_agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember_E1143146D5D5321ED67A92D56E4E090A" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_95FF349F0331B9587B9292D56E4D1F26" xlink:to="loc_agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember_E1143146D5D5321ED67A92D56E4E090A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_77D37CCC2887B01BABAD92D56E4E3FA9" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_77D37CCC2887B01BABAD92D56E4E3FA9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4BD83CC472F82BF6703392D56E4E5C42_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_77D37CCC2887B01BABAD92D56E4E3FA9" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4BD83CC472F82BF6703392D56E4E5C42_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4BD83CC472F82BF6703392D56E4E5C42" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_77D37CCC2887B01BABAD92D56E4E3FA9" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4BD83CC472F82BF6703392D56E4E5C42" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_407515813E89A040C65092D56E4E8B30" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4BD83CC472F82BF6703392D56E4E5C42" xlink:to="loc_us-gaap_PutOptionMember_407515813E89A040C65092D56E4E8B30" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_F88A6BD7A3FA29445F9192D56E4E91E3" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_F88A6BD7A3FA29445F9192D56E4E91E3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_9877B00CB1F4E50EB7E392D56E4EDF5A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_F88A6BD7A3FA29445F9192D56E4E91E3" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_9877B00CB1F4E50EB7E392D56E4EDF5A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_9877B00CB1F4E50EB7E392D56E4EDF5A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_F88A6BD7A3FA29445F9192D56E4E91E3" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_9877B00CB1F4E50EB7E392D56E4EDF5A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_F0763C5CF6F5321BA86B92D56E4E0242" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_9877B00CB1F4E50EB7E392D56E4EDF5A" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_F0763C5CF6F5321BA86B92D56E4E0242" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_FEBD8C7BCFEB45975EBC92D56E4E95B2" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_HedgingDesignationAxis_FEBD8C7BCFEB45975EBC92D56E4E95B2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_0E619D613A0881B280CA92D56E4ECBD9_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_FEBD8C7BCFEB45975EBC92D56E4E95B2" xlink:to="loc_us-gaap_HedgingDesignationDomain_0E619D613A0881B280CA92D56E4ECBD9_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_0E619D613A0881B280CA92D56E4ECBD9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_FEBD8C7BCFEB45975EBC92D56E4E95B2" xlink:to="loc_us-gaap_HedgingDesignationDomain_0E619D613A0881B280CA92D56E4ECBD9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_6F91FF9C1F01B4157D7792D56E4E84ED" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_0E619D613A0881B280CA92D56E4ECBD9" xlink:to="loc_us-gaap_NondesignatedMember_6F91FF9C1F01B4157D7792D56E4E84ED" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_74F50D41AE7364B22F7192D56E4E352F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_6FCB8DD7FC970A2D9C7792D56E47A9E0" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_74F50D41AE7364B22F7192D56E4E352F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_74F50D41AE7364B22F7192D56E4E352F" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_74F50D41AE7364B22F7192D56E4E352F" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_1BDF8CC8F653158EE29A92D56E4E1096" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_us-gaap_PutOptionMember_1BDF8CC8F653158EE29A92D56E4E1096" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TBAandForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_9B8C7C315623982652E192D56E4EE8C0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_9B8C7C315623982652E192D56E4EE8C0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_DB688BF1170D87ADB89C92D56E4EB94F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_DB688BF1170D87ADB89C92D56E4EB94F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_EB0B80666E9C43B410FA92D56E4E6216" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_EB0B80666E9C43B410FA92D56E4E6216" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_48035C7218EB1FF83E2A92D56E4E062A" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_us-gaap_InterestRateSwapMember_48035C7218EB1FF83E2A92D56E4E062A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwaptionMember" xlink:label="loc_us-gaap_InterestRateSwaptionMember_DC365F7D0442C7437F2692D56E4E9422" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_us-gaap_InterestRateSwaptionMember_DC365F7D0442C7437F2692D56E4E9422" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_203CF6F7230F65C397AC92D56E4EE849" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_agnc_PayerSwaptionMember_203CF6F7230F65C397AC92D56E4EE849" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_97153D83967DE2490C0192D56E4E2604" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_agnc_ReceiverSwaptionMember_97153D83967DE2490C0192D56E4E2604" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_E40EF04749ADA31E139092D56E4E21B3" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_E40EF04749ADA31E139092D56E4E21B3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_3D67B5E4EF656AB30E5892D56E4E539D" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A3B99CA5E4F5BDD87F7C92D56E4E847B" xlink:to="loc_us-gaap_FutureMember_3D67B5E4EF656AB30E5892D56E4E539D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OptionsAtCost" xlink:label="loc_agnc_OptionsAtCost_616BFCECF26188F7106892D56E4FDD07" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_OptionsAtCost_616BFCECF26188F7106892D56E4FDD07" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativesAtFairValueNet" xlink:label="loc_us-gaap_InterestRateDerivativesAtFairValueNet_C05AEA0D9FBFCFB265D792D56E4F61BE" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_InterestRateDerivativesAtFairValueNet_C05AEA0D9FBFCFB265D792D56E4F61BE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration" xlink:label="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_764FC9C4FEFCB674544F92D56E4FE376" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_764FC9C4FEFCB674544F92D56E4FE376" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_00FA736055F3D2E1403892D56E548936" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_00FA736055F3D2E1403892D56E548936" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_02E577343FFA414E947792D56E54BFDB" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_02E577343FFA414E947792D56E54BFDB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate" xlink:label="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_E2E0EED122AB8A57F99E92D56E5471A0" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_E2E0EED122AB8A57F99E92D56E5471A0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_D3B958F2EEED89BCB73392D56E542C5C" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_D3B958F2EEED89BCB73392D56E542C5C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_8010EB9153BE3986B8FD92D56E546DFB" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_8010EB9153BE3986B8FD92D56E546DFB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecurities" xlink:label="loc_us-gaap_TradingSecurities_9333486D192B03B9E74D92D56E541DA5" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_TradingSecurities_9333486D192B03B9E74D92D56E541DA5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TradingSecuritiesAddedDuringthePeriod" xlink:label="loc_agnc_TradingSecuritiesAddedDuringthePeriod_2E3BC92B5CE116AA571792D56E54827B" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_TradingSecuritiesAddedDuringthePeriod_2E3BC92B5CE116AA571792D56E54827B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod" xlink:label="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_9E6F04797D0684A1946692D56E54AF23" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_9E6F04797D0684A1946692D56E54AF23" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_AF22B8A61F806A9949E592D56E546DCD" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_AF22B8A61F806A9949E592D56E546DCD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_03F9A198BF9CC0E856DE92D56E54ECAA" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_03F9A198BF9CC0E856DE92D56E54ECAA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_A24AFEC45104C212A0F492D56E5496E8" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_A24AFEC45104C212A0F492D56E5496E8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_3D6AEAF58A47FE656E0B92D56E5441B2" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_3D6AEAF58A47FE656E0B92D56E5441B2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_3BC872C42448F3B3B6C292D56E549137" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_3BC872C42448F3B3B6C292D56E549137" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge" xlink:label="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_8075C2E21F546959906092D56E543223" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_8075C2E21F546959906092D56E543223" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_2382AC339EE9752B79DA92D56E541570" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_2382AC339EE9752B79DA92D56E541570" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths" xlink:label="loc_agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths_E0387824ED186AF90AD892D56E547CBD" xlink:type="locator" />
    <definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_DeferredGainLossDiscontinuedInterestRateSwapExpectedToBeReclassifiedFromOciToInterestExpenseNextTwelveMonths_E0387824ED186AF90AD892D56E547CBD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeHigherRemainingMaturityRange1" xlink:label="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_BC7156EC0A76198E833D92D56E54A873" xlink:type="locator" />
    <definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_BC7156EC0A76198E833D92D56E54A873" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_CA5DBA2A60A30BBC0BB092D56E54F93D" xlink:type="locator" />
    <definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_CA5DBA2A60A30BBC0BB092D56E54F93D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_11C9AA24828A94784B8592D56E547B91" xlink:type="locator" />
    <definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_11C9AA24828A94784B8592D56E547B91" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_66A5D6DF3DEAC1DE2FE692D56E5439DF" xlink:type="locator" />
    <definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_66A5D6DF3DEAC1DE2FE692D56E5439DF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeNetHedgeIneffectivenessGainLoss" xlink:label="loc_us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_25C0CB9F7FE3D72E5E8992D56E55FAD7" xlink:type="locator" />
    <definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_25C0CB9F7FE3D72E5E8992D56E55FAD7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditDerivativeMaximumExposureUndiscounted" xlink:label="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_3F5E887E1F79233714E192D56E554D9F" xlink:type="locator" />
    <definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5659EFF934E8FE004A592D56E4EC7CA" xlink:to="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_3F5E887E1F79233714E192D56E554D9F" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfLongAndShortPositionOfDerivativeInstrumentsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_83F2B1CBE8C1F2FCAE0A863E89F5F1E5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:to="loc_us-gaap_InvestmentTypeAxis_83F2B1CBE8C1F2FCAE0A863E89F5F1E5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_83F2B1CBE8C1F2FCAE0A863E89F5F1E5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_83F2B1CBE8C1F2FCAE0A863E89F5F1E5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_588C27E00DC535CC0E51863E89F53111" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_588C27E00DC535CC0E51863E89F53111" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherDerivativesMember" xlink:label="loc_agnc_OtherDerivativesMember_09D0A1346FE90E66F7CF863E89F53153" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_9403599B24ADECA6AD5C863E89F567BF" xlink:to="loc_agnc_OtherDerivativesMember_09D0A1346FE90E66F7CF863E89F53153" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2D63F97AA3A565EB5737863E89F5CBC6" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2D63F97AA3A565EB5737863E89F5CBC6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2D63F97AA3A565EB5737863E89F5CBC6" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2D63F97AA3A565EB5737863E89F5CBC6" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_A814E5C92F0D9E6D1F07863E89F50064" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_A814E5C92F0D9E6D1F07863E89F50064" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_CCDF6D1EB13C2671EDF3863E89F5EB16" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_A969FFF044C7410E2B64863E89F5CC49" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_CCDF6D1EB13C2671EDF3863E89F5EB16" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_85AB82321AB328AB3F60863E89F5179A" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:to="loc_us-gaap_DerivativeByNatureAxis_85AB82321AB328AB3F60863E89F5179A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_85AB82321AB328AB3F60863E89F5179A" xlink:to="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_85AB82321AB328AB3F60863E89F5179A" xlink:to="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionMember" xlink:label="loc_us-gaap_OptionMember_66F09C7CF3C4C9D4F733863F048198BF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_OptionMember_66F09C7CF3C4C9D4F733863F048198BF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_E4A4D8B2829D7CDF2170863E89F512A8" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_FutureMember_E4A4D8B2829D7CDF2170863E89F512A8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_6322ABF12A6B6A91380F863E89F54E01" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_LongMember_6322ABF12A6B6A91380F863E89F54E01" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_DF26BB14C74B1C190D2A863E89F507BE" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_NondesignatedMember_DF26BB14C74B1C190D2A863E89F507BE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_C36B22719D6C6C9E0C36863E89F568B2" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_agnc_ReceiverSwaptionMember_C36B22719D6C6C9E0C36863E89F568B2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_C384C6266673800E8257863E89F555FD" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_agnc_PayerSwaptionMember_C384C6266673800E8257863E89F555FD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_92FE7CFA9C2BA03CB755863E89F5B3F8" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_92FE7CFA9C2BA03CB755863E89F5B3F8" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember" xlink:label="loc_agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember_6FA83E794583B6395EE7863E89F5DB95" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember_6FA83E794583B6395EE7863E89F5DB95" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_3BE94416429C670BBA49863E89F51CC5" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_ForwardContractsMember_3BE94416429C670BBA49863E89F51CC5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_E61426B6A28736FEC6EE863E89F5D155" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_D87AEBC65625E463EDA7863E89F539ED" xlink:to="loc_us-gaap_ShortMember_E61426B6A28736FEC6EE863E89F5D155" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_560E04F3CC7E86FC269F863E89F5C9D5" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_16F7050F36983C113219863E89F53F8F" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_560E04F3CC7E86FC269F863E89F5C9D5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_560E04F3CC7E86FC269F863E89F5C9D5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_560E04F3CC7E86FC269F863E89F5C9D5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_E3476D94C2790340FC25863E89F58A7F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_PutOptionMember_E3476D94C2790340FC25863E89F58A7F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TBAandForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_6ED1DED92E3A20F71F00863E89F54271" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_6ED1DED92E3A20F71F00863E89F54271" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_4E438EB2576232417A9C863E89F50120" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_InterestRateSwapMember_4E438EB2576232417A9C863E89F50120" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_8C82F7353F08D994E291863E89F527CF" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_8C82F7353F08D994E291863E89F527CF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_C1ADE05386DA4412BCB9863E89F58208" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_LongMember_C1ADE05386DA4412BCB9863E89F58208" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_70300A032BAAFDBBAC5A863E89F56E36" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_ShortMember_70300A032BAAFDBBAC5A863E89F56E36" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwaptionMember" xlink:label="loc_us-gaap_InterestRateSwaptionMember_C7DEACB1E9D520631146863E89F525AE" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_InterestRateSwaptionMember_C7DEACB1E9D520631146863E89F525AE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_3ACF3E2D7E76FAF5463C863E89F51F0E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_agnc_PayerSwaptionMember_3ACF3E2D7E76FAF5463C863E89F51F0E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_70BE7E79D04E20C6D23D863E89F5F94B" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_70BE7E79D04E20C6D23D863E89F5F94B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_619227966567790CEDA3863E89F58342" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_619227966567790CEDA3863E89F58342" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_899AD6CAE794B8133ED9863E89F5BBB3" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_us-gaap_FutureMember_899AD6CAE794B8133ED9863E89F5BBB3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_6B6527E25CB7BBB1E126863E89F57396" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_984C1407B0E1D0112649863E89F5CC08" xlink:to="loc_agnc_ReceiverSwaptionMember_6B6527E25CB7BBB1E126863E89F57396" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainLossOnOtherDebt" xlink:label="loc_agnc_GainLossOnOtherDebt_8564D163225AA8F92EE2863E89F52629" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_GainLossOnOtherDebt_8564D163225AA8F92EE2863E89F52629" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_78936BA478B046DA2048863E89F562D4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_GainOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_78936BA478B046DA2048863E89F562D4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_527CE04F9C0F984308DF863E89F57B87" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_527CE04F9C0F984308DF863E89F57B87" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainlossonREITEquitySecurities" xlink:label="loc_agnc_GainlossonREITEquitySecurities_E791DB198342D9B3693C863E89F540FD" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_GainlossonREITEquitySecurities_E791DB198342D9B3693C863E89F540FD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_2818EB0D56AC76775313863E89F57B74" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_2818EB0D56AC76775313863E89F57B74" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_F91C3B07DD000C8AB093863E89F52643" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_F91C3B07DD000C8AB093863E89F52643" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_A605835C9CFD486B980B863E89F52F11" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_A605835C9CFD486B980B863E89F52F11" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_DF8649126D4B39669956863E89F5CB1E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_DF8649126D4B39669956863E89F5CB1E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings" xlink:label="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_80600031E9E4EC8C52D4863E89F5C1D3" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_LossOnInterestOnlySecuritiesRemeasuredAtFairValueThroughEarnings_80600031E9E4EC8C52D4863E89F5C1D3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativeForwardSettlementValue" xlink:label="loc_agnc_DerivativeForwardSettlementValue_D5167522D4677F57AF8F863E89F51041" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_DerivativeForwardSettlementValue_D5167522D4677F57AF8F863E89F51041" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_7A4CFF588D9C71D964D9863E89F53216" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_7A4CFF588D9C71D964D9863E89F53216" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_8556B49A12734BF01D7F863E89F59FCB" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_8556B49A12734BF01D7F863E89F59FCB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_EE5FDE38DC8D96B0CACC863E89F5BBF6" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_EE5FDE38DC8D96B0CACC863E89F5BBF6" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_13190ED25746CBBF1A42863E89F59ED1" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_13190ED25746CBBF1A42863E89F59ED1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_803D54369B70D11FAC96863E89F557F0" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_803D54369B70D11FAC96863E89F557F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecurities" xlink:label="loc_us-gaap_TradingSecurities_FCAFEEA2BC614847012A863E89F51984" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_us-gaap_TradingSecurities_FCAFEEA2BC614847012A863E89F51984" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TradingSecuritiesAddedDuringthePeriod" xlink:label="loc_agnc_TradingSecuritiesAddedDuringthePeriod_3FE0FBC9CB5DE224B780863E89F570A0" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_TradingSecuritiesAddedDuringthePeriod_3FE0FBC9CB5DE224B780863E89F570A0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod" xlink:label="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_8231010C78AAB206FF9B863E89F5B7DD" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93D5FBA2AABEE05A7D08863E89F5A694" xlink:to="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_8231010C78AAB206FF9B863E89F5B7DD" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingForwardContractsDesignatedAsHedgingInstrumentsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_5139DF877D759241C197F0C8A565856F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_us-gaap_DerivativeTable_5139DF877D759241C197F0C8A565856F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_479DBFC3C428097D1639F0C8A56550EB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_5139DF877D759241C197F0C8A565856F" xlink:to="loc_us-gaap_DerivativeByNatureAxis_479DBFC3C428097D1639F0C8A56550EB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_479DBFC3C428097D1639F0C8A56550EB" xlink:to="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_479DBFC3C428097D1639F0C8A56550EB" xlink:to="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_HedgeDeDesignationsMember" xlink:label="loc_agnc_HedgeDeDesignationsMember_0088AC35E7C44F24263FF0C8A5667E37" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:to="loc_agnc_HedgeDeDesignationsMember_0088AC35E7C44F24263FF0C8A5667E37" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalTerminationsExpirationsDuringthePeriodMemberMember" xlink:label="loc_agnc_NotionalTerminationsExpirationsDuringthePeriodMemberMember_F941ACD1958DB1B31C0DF0C8A566FF58" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:to="loc_agnc_NotionalTerminationsExpirationsDuringthePeriodMemberMember_F941ACD1958DB1B31C0DF0C8A566FF58" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAdditionsDuringthePeriodMember" xlink:label="loc_agnc_NotionalAdditionsDuringthePeriodMember_AD8CC71573D26C0E6C4DF0C8A566B7DD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:to="loc_agnc_NotionalAdditionsDuringthePeriodMember_AD8CC71573D26C0E6C4DF0C8A566B7DD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2296D4F6CDEEA08C6D51F0C8A566DE1D" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_C8ED550774173D1FEF51F0C8A5666536" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2296D4F6CDEEA08C6D51F0C8A566DE1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_8DAB38D7B27EE3111FD9F0C8A5660A1D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_5139DF877D759241C197F0C8A565856F" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_8DAB38D7B27EE3111FD9F0C8A5660A1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8DAB38D7B27EE3111FD9F0C8A5660A1D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8DAB38D7B27EE3111FD9F0C8A5660A1D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_89756262BC131558540EF0C8A5664473" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051" xlink:to="loc_us-gaap_InterestRateSwapMember_89756262BC131558540EF0C8A5664473" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_C86B5416AFD582A63EA5F0C8A5661761" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_A74C1F4277305E36A058F0C8A5667051" xlink:to="loc_agnc_PurchasesOfTbasAndForwardSettlingAgencySecuritiesMember_C86B5416AFD582A63EA5F0C8A5661761" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetPeriodicInterestRateCostsOnSwaps" xlink:label="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_CB78BBB279D38899BA37F0C8A566E4E8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_agnc_NetPeriodicInterestRateCostsOnSwaps_CB78BBB279D38899BA37F0C8A566E4E8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_3A7B1C48DA6768F52D90F0C8A5667C1D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_3A7B1C48DA6768F52D90F0C8A5667C1D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfCashFlowHedgeInstrumentsAdditionsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfCashFlowHedgeInstrumentsAdditionsDuringPeriod_4B76D1265BDC3C92077AF0C8A566AE17" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_agnc_NotionalAmountOfCashFlowHedgeInstrumentsAdditionsDuringPeriod_4B76D1265BDC3C92077AF0C8A566AE17" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfCashFlowHedgeInstrumentsSettlementsExpirationsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfCashFlowHedgeInstrumentsSettlementsExpirationsDuringPeriod_D29887F96497A5271B36F0C8A566C893" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_agnc_NotionalAmountOfCashFlowHedgeInstrumentsSettlementsExpirationsDuringPeriod_D29887F96497A5271B36F0C8A566C893" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion" xlink:label="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_3EC3CDBED09D58A5AE82F0C8A566E59F" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F108D716DD9645E6824AF0C8A56632E6" xlink:to="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_3EC3CDBED09D58A5AE82F0C8A566E59F" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsDesignatedAsHedgesInFutureDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_3C22DE356C218D5EB356F0C8A58D9C55" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_us-gaap_DerivativeTable_3C22DE356C218D5EB356F0C8A58D9C55" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityAxis" xlink:label="loc_agnc_DerivativesByMaturityAxis_214866F6070EC0F8C546F0C8A58D4E5B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3C22DE356C218D5EB356F0C8A58D9C55" xlink:to="loc_agnc_DerivativesByMaturityAxis_214866F6070EC0F8C546F0C8A58D4E5B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativesByMaturityAxis_214866F6070EC0F8C546F0C8A58D4E5B" xlink:to="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativesByMaturityAxis_214866F6070EC0F8C546F0C8A58D4E5B" xlink:to="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LessThanOrEqualToOneYearMember" xlink:label="loc_agnc_LessThanOrEqualToOneYearMember_FF374BB4E5F6F990807AF0C8A58DFD96" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:to="loc_agnc_LessThanOrEqualToOneYearMember_FF374BB4E5F6F990807AF0C8A58DFD96" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_76DB72F0CDBFE0B205FDF0C8A58DDBB1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:to="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_76DB72F0CDBFE0B205FDF0C8A58DDBB1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember_BAB4B532F350B57F7421F0C8A58D851D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:to="loc_agnc_GreaterThanTwoYearsLessThanOrEqualToThreeYearsMember_BAB4B532F350B57F7421F0C8A58D851D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember" xlink:label="loc_agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember_087D58B0C595886D132AF0C8A58D04CF" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:to="loc_agnc_GreaterThanThreeYearsLessThanOrEqualToFourYearsMember_087D58B0C595886D132AF0C8A58D04CF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember" xlink:label="loc_agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember_2A188E2256ACF171FF9EF0C8A58DD5F6" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_FEC59D0A29CE9BD95F6BF0C8A58DF140" xlink:to="loc_agnc_GreaterThanFourYearsLessThanOrEqualToFiveYearsMember_2A188E2256ACF171FF9EF0C8A58DD5F6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_6F9CE36F26BE9DF7A0C9F0C8A58D441C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3C22DE356C218D5EB356F0C8A58D9C55" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_6F9CE36F26BE9DF7A0C9F0C8A58D441C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_BF62D13CCCC3725F7D07F0C8A58DAB2C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_6F9CE36F26BE9DF7A0C9F0C8A58D441C" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_BF62D13CCCC3725F7D07F0C8A58DAB2C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_BF62D13CCCC3725F7D07F0C8A58DAB2C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_6F9CE36F26BE9DF7A0C9F0C8A58D441C" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_BF62D13CCCC3725F7D07F0C8A58DAB2C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_8F731AFDABF56498671DF0C8A58D5B44" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_BF62D13CCCC3725F7D07F0C8A58DAB2C" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_8F731AFDABF56498671DF0C8A58D5B44" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_164597ADCBFD059322E0F0C8A58D1C04" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3C22DE356C218D5EB356F0C8A58D9C55" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_164597ADCBFD059322E0F0C8A58D1C04" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_164597ADCBFD059322E0F0C8A58D1C04" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_164597ADCBFD059322E0F0C8A58D1C04" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsMember" xlink:label="loc_agnc_InterestRateSwapsMember_1507BE74E03960385510F0C8A58EBA08" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68" xlink:to="loc_agnc_InterestRateSwapsMember_1507BE74E03960385510F0C8A58EBA08" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_8692C632BA2FB1F14274F0C8A58ED06C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68" xlink:to="loc_agnc_PayerSwaptionMember_8692C632BA2FB1F14274F0C8A58ED06C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwaptionMember" xlink:label="loc_us-gaap_InterestRateSwaptionMember_14F501F1629BF9555BF3F0C8A58E5352" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_875724C52D0EE3D4A4BBF0C8A58D0D68" xlink:to="loc_us-gaap_InterestRateSwaptionMember_14F501F1629BF9555BF3F0C8A58E5352" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OptionsAtCost" xlink:label="loc_agnc_OptionsAtCost_181ADA870EAB7B0F1D75F0C8A58E9230" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_agnc_OptionsAtCost_181ADA870EAB7B0F1D75F0C8A58E9230" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativesAtFairValueNet" xlink:label="loc_us-gaap_InterestRateDerivativesAtFairValueNet_984E535AAE7AB8629EC8F0C8A58EC404" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_us-gaap_InterestRateDerivativesAtFairValueNet_984E535AAE7AB8629EC8F0C8A58EC404" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration" xlink:label="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_CE670222DB9DB9D1788CF0C8A58EA808" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_CE670222DB9DB9D1788CF0C8A58EA808" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_5371C7FC962FAA7BB444F0C8A58E21F0" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_5371C7FC962FAA7BB444F0C8A58E21F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_27F120A844521D7A08EEF0C8A58E59FC" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_27F120A844521D7A08EEF0C8A58E59FC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate" xlink:label="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_988CF0AAF777745B9FB5F0C8A58ECBB3" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_988CF0AAF777745B9FB5F0C8A58ECBB3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_68CA8BC374DF0C113CACF0C8A58EC38A" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_F7E950A6183F191E0973F0C8A58ED0C0" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_68CA8BC374DF0C113CACF0C8A58EC38A" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsAgreementsNotDesignatedAsHedgesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_01EB4C4F1F92E148105692D56E944B3D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_us-gaap_DerivativeByNatureAxis_01EB4C4F1F92E148105692D56E944B3D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_01EB4C4F1F92E148105692D56E944B3D" xlink:to="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_01EB4C4F1F92E148105692D56E944B3D" xlink:to="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_CCBDD73D78D64D28F1E992D56E958014" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:to="loc_us-gaap_NondesignatedMember_CCBDD73D78D64D28F1E992D56E958014" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_72193A77091E4A0ED22D92D56E95E18C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:to="loc_us-gaap_ShortMember_72193A77091E4A0ED22D92D56E95E18C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_06DCEA0F844AFB84829492D56E95DE3A" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_06DCEA0F844AFB84829492D56E95DE3A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_3A1F7E3803236C24A07A92D56E95C7D6" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:to="loc_us-gaap_LongMember_3A1F7E3803236C24A07A92D56E95C7D6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_670F81E4A76CE8DACA7C92D56E95C19C" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_E184AD539F86FE070DF092D56E95579A" xlink:to="loc_us-gaap_FutureMember_670F81E4A76CE8DACA7C92D56E95C19C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_E4D582667491035817E192D56E95DD78" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_us-gaap_HedgingDesignationAxis_E4D582667491035817E192D56E95DD78" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_F43EBE8CD5B6B977ABD392D56E95C3BE_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_E4D582667491035817E192D56E95DD78" xlink:to="loc_us-gaap_HedgingDesignationDomain_F43EBE8CD5B6B977ABD392D56E95C3BE_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_F43EBE8CD5B6B977ABD392D56E95C3BE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_E4D582667491035817E192D56E95DD78" xlink:to="loc_us-gaap_HedgingDesignationDomain_F43EBE8CD5B6B977ABD392D56E95C3BE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_42712EC1AD9AEE9A621892D56E9575F2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_F43EBE8CD5B6B977ABD392D56E95C3BE" xlink:to="loc_us-gaap_NondesignatedMember_42712EC1AD9AEE9A621892D56E9575F2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityAxis" xlink:label="loc_agnc_DerivativesByMaturityAxis_C6BFD43EF027ECD4D25992D56E9599FD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_agnc_DerivativesByMaturityAxis_C6BFD43EF027ECD4D25992D56E9599FD" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativesByMaturityAxis_C6BFD43EF027ECD4D25992D56E9599FD" xlink:to="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativesByMaturityAxis_C6BFD43EF027ECD4D25992D56E9599FD" xlink:to="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_5DEC27E91FD64967557192D56E9A0AB0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:to="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_5DEC27E91FD64967557192D56E9A0AB0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember" xlink:label="loc_agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember_1902724BF0E9F3E5390292D56E9ABF35" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:to="loc_agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember_1902724BF0E9F3E5390292D56E9ABF35" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanFiveYearsAndLessThanOrEqualToSevenYearsMember" xlink:label="loc_agnc_GreaterThanFiveYearsAndLessThanOrEqualToSevenYearsMember_0716A7D1D8FA89FEB95A92D56E9A1084" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:to="loc_agnc_GreaterThanFiveYearsAndLessThanOrEqualToSevenYearsMember_0716A7D1D8FA89FEB95A92D56E9A1084" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanSevenYearsAndLessThanOrEqualToTenYearsMember" xlink:label="loc_agnc_GreaterThanSevenYearsAndLessThanOrEqualToTenYearsMember_BE7D2E5989D625C9853D92D56E9A32B7" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:to="loc_agnc_GreaterThanSevenYearsAndLessThanOrEqualToTenYearsMember_BE7D2E5989D625C9853D92D56E9A32B7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanTenYearsMember" xlink:label="loc_agnc_GreaterThanTenYearsMember_0CED8B3BA639E68DCBF192D56E9AB55E" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_C98326C5198C3A9BCE9192D56E953714" xlink:to="loc_agnc_GreaterThanTenYearsMember_0CED8B3BA639E68DCBF192D56E9AB55E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_BE8F2F691B17A3A8C29492D56E9A2AF2" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_BE8F2F691B17A3A8C29492D56E9A2AF2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_5A3853AFA5DC26F82A8992D56E9A76BD_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_BE8F2F691B17A3A8C29492D56E9A2AF2" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_5A3853AFA5DC26F82A8992D56E9A76BD_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_5A3853AFA5DC26F82A8992D56E9A76BD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_BE8F2F691B17A3A8C29492D56E9A2AF2" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_5A3853AFA5DC26F82A8992D56E9A76BD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_7614D9F27A30A3EF4ECD92D56E9B72B7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_5A3853AFA5DC26F82A8992D56E9A76BD" xlink:to="loc_us-gaap_PutOptionMember_7614D9F27A30A3EF4ECD92D56E9B72B7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_526BB872041826B7A95D92D56E9BF4A0" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_526BB872041826B7A95D92D56E9BF4A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_526BB872041826B7A95D92D56E9BF4A0" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_526BB872041826B7A95D92D56E9BF4A0" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativeLiabilitiesAtFairValueMember" xlink:label="loc_agnc_DerivativeLiabilitiesAtFairValueMember_EDF3438749FAC1F51F5092D56E9BD300" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF" xlink:to="loc_agnc_DerivativeLiabilitiesAtFairValueMember_EDF3438749FAC1F51F5092D56E9BD300" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativeAssetsAtFairValueMember" xlink:label="loc_agnc_DerivativeAssetsAtFairValueMember_EDB27071D9B91EE02CB192D56E9B85E7" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_2B0776FE53B097C2115892D56E9B01AF" xlink:to="loc_agnc_DerivativeAssetsAtFairValueMember_EDB27071D9B91EE02CB192D56E9B85E7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_C8F3EC0D05B1D849872C92D56E9B7DB7" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E48DFD04368B0E8D72F192D56E946FEA" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_C8F3EC0D05B1D849872C92D56E9B7DB7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C8F3EC0D05B1D849872C92D56E9B7DB7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C8F3EC0D05B1D849872C92D56E9B7DB7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TotalReturnSwapMember" xlink:label="loc_us-gaap_TotalReturnSwapMember_6F6C49B3DE1CE8417DE992D56E9B0DE2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_TotalReturnSwapMember_6F6C49B3DE1CE8417DE992D56E9B0DE2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_B34F31C7BFB0554CEF5792D56E9B66B8" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_InterestRateSwapMember_B34F31C7BFB0554CEF5792D56E9B66B8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwaptionMember" xlink:label="loc_us-gaap_InterestRateSwaptionMember_CFCE71F5D1C8C42F54BA92D56E9BE3D5" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_InterestRateSwaptionMember_CFCE71F5D1C8C42F54BA92D56E9BE3D5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_MarkitIosTotalReturnSwapsShortMember" xlink:label="loc_agnc_MarkitIosTotalReturnSwapsShortMember_EFF7A96E8BFE0C6F4C6C92D56E9BEB5A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_MarkitIosTotalReturnSwapsShortMember_EFF7A96E8BFE0C6F4C6C92D56E9BEB5A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_64AD1506354571377FAE92D56E9B1C03" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_FutureMember_64AD1506354571377FAE92D56E9B1C03" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverInterestRateSwapsMember" xlink:label="loc_agnc_ReceiverInterestRateSwapsMember_7C9BAA0E4C63B206CC1C92D56E9B73CB" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_ReceiverInterestRateSwapsMember_7C9BAA0E4C63B206CC1C92D56E9B73CB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SwaptionMember" xlink:label="loc_us-gaap_SwaptionMember_9A9033563682D29FA7F292D56E9B5A13" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_SwaptionMember_9A9033563682D29FA7F292D56E9B5A13" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TreasuryFuturesMember" xlink:label="loc_agnc_TreasuryFuturesMember_6D59742C9573353FD4CD92D56E9B937B" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_TreasuryFuturesMember_6D59742C9573353FD4CD92D56E9B937B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TBAandForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_EED9BD203F3EC56932DD92D56E9BD4F3" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_EED9BD203F3EC56932DD92D56E9BD4F3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_DDFCF4A1C8225BE6DD0892D56E9B3E1B" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_ReceiverSwaptionMember_DDFCF4A1C8225BE6DD0892D56E9B3E1B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_MarkitIosTotalReturnSwapsLongMember" xlink:label="loc_agnc_MarkitIosTotalReturnSwapsLongMember_CC6EDEADD2C8EA5C07CB92D56E9BEC4C" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_MarkitIosTotalReturnSwapsLongMember_CC6EDEADD2C8EA5C07CB92D56E9BEC4C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_5F73973C280725EA0A8C92D56E9B55D2" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_5F73973C280725EA0A8C92D56E9B55D2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_C932693107DA101B84C992D56E9B0091" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_C932693107DA101B84C992D56E9B0091" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_1753DF248447F392A7F792D56E9B501F" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_45AB6A4CC574E499EDA192D56E9B7B7A" xlink:to="loc_us-gaap_PutOptionMember_1753DF248447F392A7F792D56E9B501F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_63AA05F5C3D2629E7945930B59297ED0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_63AA05F5C3D2629E7945930B59297ED0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainOnDerivativeInstrumentsAndTradingSecurities" xlink:label="loc_agnc_GainOnDerivativeInstrumentsAndTradingSecurities_7F193F0E542175D228B192D56E9C4E86" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_GainOnDerivativeInstrumentsAndTradingSecurities_7F193F0E542175D228B192D56E9C4E86" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_3E9DCF0014F997FCF1CA92D56E9C5016" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_3E9DCF0014F997FCF1CA92D56E9C5016" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_5754F5009061C994522792D56E9C6D54" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_5754F5009061C994522792D56E9C6D54" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_9932CAAF605A532D94ED92D56E9C5D09" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_9932CAAF605A532D94ED92D56E9C5D09" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet" xlink:label="loc_us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet_EA8C5E30893F669D7C6392D56E9C0E1F" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet_EA8C5E30893F669D7C6392D56E9C0E1F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_F3A1D369C2670BFE42A192D56E9C145F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_F3A1D369C2670BFE42A192D56E9C145F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_788C1BE21041E4397F5E92D56E9CEAEB" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDuringPeriod_788C1BE21041E4397F5E92D56E9CEAEB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_84100B1C052EE1CBE53A92D56E9CAC0A" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsAdditionsDueToHedgeDeDesignations_84100B1C052EE1CBE53A92D56E9CAC0A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod" xlink:label="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_2A4FC90AB3C18DD5E93A92D56E9CDE16" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_NotionalAmountOfDerivativesNotDesignatedAsHedgingInstrumentsSettlementExpirationDuringPeriod_2A4FC90AB3C18DD5E93A92D56E9CDE16" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_B4EAEC91A3101D58F48192D56E9CC8D4" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_B4EAEC91A3101D58F48192D56E9CC8D4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TradingSecuritiesAddedDuringthePeriod" xlink:label="loc_agnc_TradingSecuritiesAddedDuringthePeriod_C9C39ACA27AFE4AAADB792D56E9CEAE3" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_TradingSecuritiesAddedDuringthePeriod_C9C39ACA27AFE4AAADB792D56E9CEAE3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod" xlink:label="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_C8C7BB77BE84D3BAF7C192D56E9C70A0" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_agnc_NotionalAmountOfTradingSecuritiesSettlementExpirationDuringThePeriod_C8C7BB77BE84D3BAF7C192D56E9C70A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecurities" xlink:label="loc_us-gaap_TradingSecurities_9784ACA4C3733074780792D56E9C6FF4" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_TradingSecurities_9784ACA4C3733074780792D56E9C6FF4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_B972F9FAFA787540742B92D56E9CC99C" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_B972F9FAFA787540742B92D56E9CC99C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell" xlink:label="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_2FB55A25F1D4DF69BBA692D56E9C2C99" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_ProceedsFromSecuritiesPurchasedUnderAgreementsToResell_2FB55A25F1D4DF69BBA692D56E9C2C99" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_F3367D024BFDB6D4F69E92D56E9C613F" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_F3367D024BFDB6D4F69E92D56E9C613F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageVariableInterestRate" xlink:label="loc_us-gaap_DerivativeAverageVariableInterestRate_8251E1293A06FBAA94FA92D56E9C08F6" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_C3231E94D0B245AA0BD892D56E9B366E" xlink:to="loc_us-gaap_DerivativeAverageVariableInterestRate_8251E1293A06FBAA94FA92D56E9C08F6" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDesignatedAsHedgingInstrumentsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionAxis" xlink:label="loc_agnc_DerivativePositionAxis_35F2A22CEE1BFBACB30AACAC9218BA0C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:to="loc_agnc_DerivativePositionAxis_35F2A22CEE1BFBACB30AACAC9218BA0C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_F8AAA66A37035D2E1CAEACAC92AD945E_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativePositionAxis_35F2A22CEE1BFBACB30AACAC9218BA0C" xlink:to="loc_agnc_DerivativePositionDomain_F8AAA66A37035D2E1CAEACAC92AD945E_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_F8AAA66A37035D2E1CAEACAC92AD945E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativePositionAxis_35F2A22CEE1BFBACB30AACAC9218BA0C" xlink:to="loc_agnc_DerivativePositionDomain_F8AAA66A37035D2E1CAEACAC92AD945E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_61BF8066A2554CF9A714ACAC945A7B57" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativePositionDomain_F8AAA66A37035D2E1CAEACAC92AD945E" xlink:to="loc_us-gaap_InterestRateSwapMember_61BF8066A2554CF9A714ACAC945A7B57" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_FB8A3AA524027F233115ACA893952EDE" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_FB8A3AA524027F233115ACA893952EDE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_FB8A3AA524027F233115ACA893952EDE" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_FB8A3AA524027F233115ACA893952EDE" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_A6892C1687AAD417100FACA893950805" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769" xlink:to="loc_us-gaap_InterestRateSwapMember_A6892C1687AAD417100FACA893950805" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsMember" xlink:label="loc_agnc_InterestRateSwapsMember_15A88D8C640F72420B5BACA89395F055" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_624698B255CD9AC5820EACA89395E769" xlink:to="loc_agnc_InterestRateSwapsMember_15A88D8C640F72420B5BACA89395F055" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_0D37C135B161E8AB2EE0ACA89395F59F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_0D37C135B161E8AB2EE0ACA89395F59F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_02C37F2A977B6A3C9114ACA893952655_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_0D37C135B161E8AB2EE0ACA89395F59F" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_02C37F2A977B6A3C9114ACA893952655_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_02C37F2A977B6A3C9114ACA893952655" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_0D37C135B161E8AB2EE0ACA89395F59F" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_02C37F2A977B6A3C9114ACA893952655" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_E8AF9D78635199C3DEB3ACA893954954" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_02C37F2A977B6A3C9114ACA893952655" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_E8AF9D78635199C3DEB3ACA893954954" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_94FE6050B03330D196DEACA89396CAAA" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F3E15423E7B8883304D4ACA89395150C" xlink:to="loc_us-gaap_DerivativeByNatureAxis_94FE6050B03330D196DEACA89396CAAA" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_94FE6050B03330D196DEACA89396CAAA" xlink:to="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_94FE6050B03330D196DEACA89396CAAA" xlink:to="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_AAEB420860BBC7B5C13BACA893969204" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142" xlink:to="loc_us-gaap_ForwardContractsMember_AAEB420860BBC7B5C13BACA893969204" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsExcludingForwardStartingMember" xlink:label="loc_agnc_InterestRateSwapsExcludingForwardStartingMember_DF180F2BFF2C27EE33E9ACA893964E11" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_35D60B2A7A3038C8ADC6ACA89396D142" xlink:to="loc_agnc_InterestRateSwapsExcludingForwardStartingMember_DF180F2BFF2C27EE33E9ACA893964E11" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_291D546BBE189A94B7C3ACA89396DBA1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_291D546BBE189A94B7C3ACA89396DBA1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion" xlink:label="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_0EEFB6517B208CCBB6F7ACA893962EBF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_0EEFB6517B208CCBB6F7ACA893962EBF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_6AD4672A9F3150D298EAACA89396A450" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_invest_DerivativeNotionalAmount_6AD4672A9F3150D298EAACA89396A450" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_06F5E79A7E4E6284DE02ACA89396DB73" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_06F5E79A7E4E6284DE02ACA89396DB73" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeHigherRemainingMaturityRange1" xlink:label="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_EAB591A9423D7BCEACE3ACA89396CE1D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_EAB591A9423D7BCEACE3ACA89396CE1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_950504FB4EC916CAA3A4ACA893962346" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_4A65E384A1B18F77AD6DACA893968857" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_950504FB4EC916CAA3A4ACA893962346" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingInterestRateSwapsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityAxis" xlink:label="loc_agnc_DerivativesByMaturityAxis_7C071446CE73D3C5D277ACA89726B57D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:to="loc_agnc_DerivativesByMaturityAxis_7C071446CE73D3C5D277ACA89726B57D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_48DBD48ED220E992E4C9ACA897269D70_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativesByMaturityAxis_7C071446CE73D3C5D277ACA89726B57D" xlink:to="loc_agnc_DerivativesByMaturityDomain_48DBD48ED220E992E4C9ACA897269D70_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativesByMaturityDomain" xlink:label="loc_agnc_DerivativesByMaturityDomain_48DBD48ED220E992E4C9ACA897269D70" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativesByMaturityAxis_7C071446CE73D3C5D277ACA89726B57D" xlink:to="loc_agnc_DerivativesByMaturityDomain_48DBD48ED220E992E4C9ACA897269D70" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LessThanOrEqualToOneYearMember" xlink:label="loc_agnc_LessThanOrEqualToOneYearMember_A64AC02C5398F900AD0EACA897265327" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativesByMaturityDomain_48DBD48ED220E992E4C9ACA897269D70" xlink:to="loc_agnc_LessThanOrEqualToOneYearMember_A64AC02C5398F900AD0EACA897265327" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_667DEB1324D063014FE2ACA8972658E2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:to="loc_us-gaap_DerivativeByNatureAxis_667DEB1324D063014FE2ACA8972658E2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_667DEB1324D063014FE2ACA8972658E2" xlink:to="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_667DEB1324D063014FE2ACA8972658E2" xlink:to="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_D5714EFB80ED08A93149ACAF2DC63332" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7" xlink:to="loc_us-gaap_ForwardContractsMember_D5714EFB80ED08A93149ACAF2DC63332" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsExcludingForwardStartingMember" xlink:label="loc_agnc_InterestRateSwapsExcludingForwardStartingMember_F1EF39739A1AEF2C2E8CACA897264FF7" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_73099F41C1E9DC403977ACA8972620F7" xlink:to="loc_agnc_InterestRateSwapsExcludingForwardStartingMember_F1EF39739A1AEF2C2E8CACA897264FF7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionAxis" xlink:label="loc_agnc_DerivativePositionAxis_65972811F51AC9302461ACA897264DF2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:to="loc_agnc_DerivativePositionAxis_65972811F51AC9302461ACA897264DF2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_E250BFB3BB22F7BAAF8AACA89726377B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_DerivativePositionAxis_65972811F51AC9302461ACA897264DF2" xlink:to="loc_agnc_DerivativePositionDomain_E250BFB3BB22F7BAAF8AACA89726377B_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativePositionDomain" xlink:label="loc_agnc_DerivativePositionDomain_E250BFB3BB22F7BAAF8AACA89726377B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_DerivativePositionAxis_65972811F51AC9302461ACA897264DF2" xlink:to="loc_agnc_DerivativePositionDomain_E250BFB3BB22F7BAAF8AACA89726377B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_C8F2E7BFB969F18AF2CEACA897267125" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativePositionDomain_E250BFB3BB22F7BAAF8AACA89726377B" xlink:to="loc_us-gaap_InterestRateSwapMember_C8F2E7BFB969F18AF2CEACA897267125" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_74149F6CE7D3286CB328ACA897269D34" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_74149F6CE7D3286CB328ACA897269D34" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_DCB8DBDE2D9626461F7CACA89726CA5F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_74149F6CE7D3286CB328ACA897269D34" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_DCB8DBDE2D9626461F7CACA89726CA5F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_DCB8DBDE2D9626461F7CACA89726CA5F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_74149F6CE7D3286CB328ACA897269D34" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_DCB8DBDE2D9626461F7CACA89726CA5F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_0A93A5883C3512B3C21DACA8972682EF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_DCB8DBDE2D9626461F7CACA89726CA5F" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_0A93A5883C3512B3C21DACA8972682EF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_C9EA31860F5F98485F4FACA89726653B" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A4CCC33A9CFEABB3A3DACA89726D3B6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_C9EA31860F5F98485F4FACA89726653B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C9EA31860F5F98485F4FACA89726653B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_C9EA31860F5F98485F4FACA89726653B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReceiverSwaptionMember" xlink:label="loc_agnc_ReceiverSwaptionMember_BB02BC6507B652D1491DACA8972612FB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142" xlink:to="loc_agnc_ReceiverSwaptionMember_BB02BC6507B652D1491DACA8972612FB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_5E722E1A0D06E0180485ACA89727FE97" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_90EF8E05632559CF3A0BACA897261142" xlink:to="loc_us-gaap_InterestRateSwapMember_5E722E1A0D06E0180485ACA89727FE97" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OptionsAtCost" xlink:label="loc_agnc_OptionsAtCost_2E05563432E255B9FF02ACA8972740BF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_agnc_OptionsAtCost_2E05563432E255B9FF02ACA8972740BF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_08A814D5278FE746DC5BACA897270295" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_invest_DerivativeNotionalAmount_08A814D5278FE746DC5BACA897270295" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeHigherRemainingMaturityRange1" xlink:label="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_BE261BD4460DAEFE1467ACA8972705CD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeHigherRemainingMaturityRange1_BE261BD4460DAEFE1467ACA8972705CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate_D67D3E0C38AAE4C805FEACA89727029D" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeAverageFixedInterestRate_D67D3E0C38AAE4C805FEACA89727029D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion" xlink:label="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_34EE16B4D8FFA5010173ACA89727E42D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion_34EE16B4D8FFA5010173ACA89727E42D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_EF3F1F2FFF9D45201127ACA897278A6D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_EF3F1F2FFF9D45201127ACA897278A6D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativesAtFairValueNet" xlink:label="loc_us-gaap_InterestRateDerivativesAtFairValueNet_66DE7038DF879BFC0C7AACA897279183" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_InterestRateDerivativesAtFairValueNet_66DE7038DF879BFC0C7AACA897279183" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration" xlink:label="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_10A940443C394CCA8B66ACA897274732" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_agnc_CashFlowHedgesDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAverageMonthsToExpiration_10A940443C394CCA8B66ACA897274732" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_8BE98179A4D1B072D783ACA89727EAF1" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_8BE98179A4D1B072D783ACA89727EAF1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate" xlink:label="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_143831AADD997E1698E8ACA89727D391" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_agnc_InterestRateDerivativeNotDesignatedAsHedgingInstrumentsReceiveRate_143831AADD997E1698E8ACA89727D391" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAverageRemainingMaturity1" xlink:label="loc_us-gaap_DerivativeAverageRemainingMaturity1_C30D7D0473AD4B0D5A09ACA897277C60" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E9392B0D55F0C3E66C61ACA897276469" xlink:to="loc_us-gaap_DerivativeAverageRemainingMaturity1_C30D7D0473AD4B0D5A09ACA897277C60" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsSummaryOfOutstandingTbasDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_F27C0C87215703284DA8F0C8A505FA8C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_us-gaap_DerivativeTable_F27C0C87215703284DA8F0C8A505FA8C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_021FA5C922D85051573CF0C8A506E1D8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F27C0C87215703284DA8F0C8A505FA8C" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_021FA5C922D85051573CF0C8A506E1D8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_021FA5C922D85051573CF0C8A506E1D8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_021FA5C922D85051573CF0C8A506E1D8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_D166CD1CAAF8EFA8B57FF0C8A5067B39" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB" xlink:to="loc_us-gaap_LongMember_D166CD1CAAF8EFA8B57FF0C8A5067B39" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_6EB06EC5E3575994EE00F0C8A506CBE6" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_F52699807DF1FB3BA596F0C8A506D8EB" xlink:to="loc_us-gaap_ShortMember_6EB06EC5E3575994EE00F0C8A506CBE6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_4BD1FD45BAFF10FF5215F0C8A506989F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_F27C0C87215703284DA8F0C8A505FA8C" xlink:to="loc_us-gaap_DerivativeByNatureAxis_4BD1FD45BAFF10FF5215F0C8A506989F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_4BD1FD45BAFF10FF5215F0C8A506989F" xlink:to="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_4BD1FD45BAFF10FF5215F0C8A506989F" xlink:to="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember" xlink:label="loc_agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember_507310A66BD8BDFA2EBDF0C8A50686B1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295" xlink:to="loc_agnc_TbaSecuritiesFifteenYearAndThirtyYearSecuritiesMember_507310A66BD8BDFA2EBDF0C8A50686B1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_AA9BF73FC431B2007344F0C8A50640E6" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_6A4EBEE4F8BFD2AD8D28F0C8A5061295" xlink:to="loc_us-gaap_ForwardContractsMember_AA9BF73FC431B2007344F0C8A50640E6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_2F29118313D129542D37F0C8A5065243" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_2F29118313D129542D37F0C8A5065243" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_4D19D57CC356F4140959F0C8A506DB99" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_4D19D57CC356F4140959F0C8A506DB99" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_049355F20A3C081F8E9DF0C8A5061A45" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_invest_DerivativeNotionalAmount_049355F20A3C081F8E9DF0C8A5061A45" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativeForwardSettlementValue" xlink:label="loc_agnc_DerivativeForwardSettlementValue_66AEFAF6633E73BEE009F0C8A506A1C2" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_agnc_DerivativeForwardSettlementValue_66AEFAF6633E73BEE009F0C8A506A1C2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecuredDebtDollarRolls" xlink:label="loc_us-gaap_SecuredDebtDollarRolls_FC94C5D5BA3A39DD23BCF0C8A508CDA9" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_us-gaap_SecuredDebtDollarRolls_FC94C5D5BA3A39DD23BCF0C8A508CDA9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_C7686F8E0B534D1544E5F0C8A5086F62" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_449F5A8484AC0A9650D5F0C8A506E4BC" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_C7686F8E0B534D1544E5F0C8A5086F62" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DerivativeAndOtherHedgingInstrumentsTables" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_CFB9C07813C0115B58F1F0C8A53B3FA3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_us-gaap_DerivativeTable_CFB9C07813C0115B58F1F0C8A53B3FA3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_2A7400772BAA5F75A530F0C8A53C03AD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_CFB9C07813C0115B58F1F0C8A53B3FA3" xlink:to="loc_us-gaap_HedgingDesignationAxis_2A7400772BAA5F75A530F0C8A53C03AD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_EE24338CFA0ADA4FCC8EF0C8A53CD7DA_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_2A7400772BAA5F75A530F0C8A53C03AD" xlink:to="loc_us-gaap_HedgingDesignationDomain_EE24338CFA0ADA4FCC8EF0C8A53CD7DA_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_EE24338CFA0ADA4FCC8EF0C8A53CD7DA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_2A7400772BAA5F75A530F0C8A53C03AD" xlink:to="loc_us-gaap_HedgingDesignationDomain_EE24338CFA0ADA4FCC8EF0C8A53CD7DA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_1E12C3D8FD317C26B0D0F0C8A53C7296" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_EE24338CFA0ADA4FCC8EF0C8A53CD7DA" xlink:to="loc_us-gaap_NondesignatedMember_1E12C3D8FD317C26B0D0F0C8A53C7296" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock_EF7B1568F26CD5969BD5F0C8A53C7050" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock_EF7B1568F26CD5969BD5F0C8A53C7050" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleOfOutstandingDerivativesNotDesignatedAsHedgingInstrumentsTableTextBlock" xlink:label="loc_agnc_ScheduleOfOutstandingDerivativesNotDesignatedAsHedgingInstrumentsTableTextBlock_CADEA0EDF45F32227D61F0C8A53C002C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_agnc_ScheduleOfOutstandingDerivativesNotDesignatedAsHedgingInstrumentsTableTextBlock_CADEA0EDF45F32227D61F0C8A53C002C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleOfInterestRateSwapAgreementByRemainingMaturityTableTextBlock" xlink:label="loc_agnc_ScheduleOfInterestRateSwapAgreementByRemainingMaturityTableTextBlock_F7DAED4E2D0B79351B5CF0C8A53CC417" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_agnc_ScheduleOfInterestRateSwapAgreementByRemainingMaturityTableTextBlock_F7DAED4E2D0B79351B5CF0C8A53CC417" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleOfInterestRateSwaptionAgreementsOutstandinTableTextBlock" xlink:label="loc_agnc_ScheduleOfInterestRateSwaptionAgreementsOutstandinTableTextBlock_A88F67F62B933078ECF0F0C8A53C9489" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_agnc_ScheduleOfInterestRateSwaptionAgreementsOutstandinTableTextBlock_A88F67F62B933078ECF0F0C8A53C9489" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleOfLongAndShortPositionOfDerivativeInstrumentsTableTextBlock" xlink:label="loc_agnc_ScheduleOfLongAndShortPositionOfDerivativeInstrumentsTableTextBlock_EFD4DD5D4321492A0222F0C8A53C76EC" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_agnc_ScheduleOfLongAndShortPositionOfDerivativeInstrumentsTableTextBlock_EFD4DD5D4321492A0222F0C8A53C76EC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleOfOutstandingNotDesignatedAsHedgingInstrumentsTableTextBlock" xlink:label="loc_agnc_ScheduleOfOutstandingNotDesignatedAsHedgingInstrumentsTableTextBlock_01FD5C47C24834166360F0C8A53C319D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_849101248B208A80EBC3F0C8A53C1682" xlink:to="loc_agnc_ScheduleOfOutstandingNotDesignatedAsHedgingInstrumentsTableTextBlock_01FD5C47C24834166360F0C8A53C319D" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/FairValueMeasurements" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_FD70ACF6D26FD3D48E92F0C8A4FACDEF" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_E412F25B50C4D29BBF40F0C8A4FA6680" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_FD70ACF6D26FD3D48E92F0C8A4FACDEF" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_E412F25B50C4D29BBF40F0C8A4FA6680" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_D1F761E65CDAA34AD7B3F0C8A4FA932F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_E412F25B50C4D29BBF40F0C8A4FA6680" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_D1F761E65CDAA34AD7B3F0C8A4FA932F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_B8BA4C0DD7C47D5C457FF0C8A4FA58F6_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_D1F761E65CDAA34AD7B3F0C8A4FA932F" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B8BA4C0DD7C47D5C457FF0C8A4FA58F6_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_B8BA4C0DD7C47D5C457FF0C8A4FA58F6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_D1F761E65CDAA34AD7B3F0C8A4FA932F" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B8BA4C0DD7C47D5C457FF0C8A4FA58F6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E820AFF218C3457FEE6CF0C8A4FA7D7A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_E412F25B50C4D29BBF40F0C8A4FA6680" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E820AFF218C3457FEE6CF0C8A4FA7D7A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7F42DE60199EE3CB4D5BF0C8A4FAA734_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E820AFF218C3457FEE6CF0C8A4FA7D7A" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7F42DE60199EE3CB4D5BF0C8A4FAA734_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7F42DE60199EE3CB4D5BF0C8A4FAA734" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E820AFF218C3457FEE6CF0C8A4FA7D7A" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7F42DE60199EE3CB4D5BF0C8A4FAA734" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="loc_us-gaap_FairValueDisclosuresTextBlock_257ECB7F1C836863C454F0C8A4FAD5AE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_FD70ACF6D26FD3D48E92F0C8A4FACDEF" xlink:to="loc_us-gaap_FairValueDisclosuresTextBlock_257ECB7F1C836863C454F0C8A4FAD5AE" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_766D700DCAC65E151A3892D56D94B8D9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_DerivativeByNatureAxis_766D700DCAC65E151A3892D56D94B8D9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_C5A60521AABE213FA4D592D56D949FA6_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_766D700DCAC65E151A3892D56D94B8D9" xlink:to="loc_agnc_DerivativebyNatureDomain_C5A60521AABE213FA4D592D56D949FA6_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_C5A60521AABE213FA4D592D56D949FA6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_766D700DCAC65E151A3892D56D94B8D9" xlink:to="loc_agnc_DerivativebyNatureDomain_C5A60521AABE213FA4D592D56D949FA6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_99A4E6EB355588483BB392D56D94BD1E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_C5A60521AABE213FA4D592D56D949FA6" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_99A4E6EB355588483BB392D56D94BD1E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_B5F39AE0D5C8CC5AB8FF92D56D945E32" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_dei_LegalEntityAxis_B5F39AE0D5C8CC5AB8FF92D56D945E32" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_B5F39AE0D5C8CC5AB8FF92D56D945E32" xlink:to="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_B5F39AE0D5C8CC5AB8FF92D56D945E32" xlink:to="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MortgageBackedSecuritiesMember" xlink:label="loc_us-gaap_MortgageBackedSecuritiesMember_8CBDC8AE3D1EFB911AE692D56D94591C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350" xlink:to="loc_us-gaap_MortgageBackedSecuritiesMember_8CBDC8AE3D1EFB911AE692D56D94591C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TreasuryFuturesShortMember" xlink:label="loc_agnc_TreasuryFuturesShortMember_0C3E6DEC644249FDF0FD92D56D94936B" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350" xlink:to="loc_agnc_TreasuryFuturesShortMember_0C3E6DEC644249FDF0FD92D56D94936B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_AA9374693119C4D36C2192D56D94F30F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01C4F846F2F07978E7D992D56D94D350" xlink:to="loc_us-gaap_InterestRateSwapMember_AA9374693119C4D36C2192D56D94F30F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_5440D81A0AE7A97BF27F92D56D94D42E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_5440D81A0AE7A97BF27F92D56D94D42E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5440D81A0AE7A97BF27F92D56D94D42E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5440D81A0AE7A97BF27F92D56D94D42E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_22A417F371CA3C87346892D56D946A08" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_22A417F371CA3C87346892D56D946A08" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwaptionMember" xlink:label="loc_us-gaap_InterestRateSwaptionMember_D1A995973134D998D8C892D56D940A15" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_us-gaap_InterestRateSwaptionMember_D1A995973134D998D8C892D56D940A15" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_ECB234BBBA816B18FB7992D56D948268" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_us-gaap_InterestRateSwapMember_ECB234BBBA816B18FB7992D56D948268" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FutureMember" xlink:label="loc_us-gaap_FutureMember_DD6D9197070CE24C5DF692D56D94D22C" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_us-gaap_FutureMember_DD6D9197070CE24C5DF692D56D94D22C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_01C2FF8251B06EDB92AC92D56D94FC18" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_us-gaap_PutOptionMember_01C2FF8251B06EDB92AC92D56D94FC18" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PayerSwaptionMember" xlink:label="loc_agnc_PayerSwaptionMember_6E3AA5325F47E836690792D56D94066D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_agnc_PayerSwaptionMember_6E3AA5325F47E836690792D56D94066D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TreasuryFuturesShortMember" xlink:label="loc_agnc_TreasuryFuturesShortMember_A332E6A4131337E57DC592D56D94D19B" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_98DB90EEB23D8328E24C92D56D94A982" xlink:to="loc_agnc_TreasuryFuturesShortMember_A332E6A4131337E57DC592D56D94D19B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_7721F924156A5015B46C92D56D94B97A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_7721F924156A5015B46C92D56D94B97A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_4E7C620B5B9089B34E2892D56D94D9C9_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_7721F924156A5015B46C92D56D94B97A" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_4E7C620B5B9089B34E2892D56D94D9C9_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_4E7C620B5B9089B34E2892D56D94D9C9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_7721F924156A5015B46C92D56D94B97A" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_4E7C620B5B9089B34E2892D56D94D9C9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember" xlink:label="loc_us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_E6EE8AF597704E6A9A2192D56D947BF6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4E7C620B5B9089B34E2892D56D94D9C9" xlink:to="loc_us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_E6EE8AF597704E6A9A2192D56D947BF6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2A91A1CEBF78743D88E892D56D946615" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2A91A1CEBF78743D88E892D56D946615" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_F71B31940FB514A7134092D56D94C9CB_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2A91A1CEBF78743D88E892D56D946615" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_F71B31940FB514A7134092D56D94C9CB_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_F71B31940FB514A7134092D56D94C9CB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2A91A1CEBF78743D88E892D56D946615" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_F71B31940FB514A7134092D56D94C9CB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_C644ADBA7EC02CF4137092D56D959EBE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_F71B31940FB514A7134092D56D94C9CB" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_C644ADBA7EC02CF4137092D56D959EBE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ADE45D249A80CB1B7D1B92D56D957485" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ADE45D249A80CB1B7D1B92D56D957485" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ADE45D249A80CB1B7D1B92D56D957485" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ADE45D249A80CB1B7D1B92D56D957485" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_C1DBADD4DB102AEF45C492D56D9AB0C5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_C1DBADD4DB102AEF45C492D56D9AB0C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_3CD7752FD4FE14A1900A92D56D9AF934" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8F987EF6C0BC5DC0D3F192D56D95A88F" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_3CD7752FD4FE14A1900A92D56D9AF934" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_206F3E9A4916D621FDEF92D56D9AEEA1" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_206F3E9A4916D621FDEF92D56D9AEEA1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_206F3E9A4916D621FDEF92D56D9AEEA1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_206F3E9A4916D621FDEF92D56D9AEEA1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PutOptionMember" xlink:label="loc_us-gaap_PutOptionMember_CB076FFCE87F3017FEE492D56D9A7F64" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_us-gaap_PutOptionMember_CB076FFCE87F3017FEE492D56D9A7F64" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SwaptionMember" xlink:label="loc_us-gaap_SwaptionMember_B93C292898BB70F110B492D56D9A1F02" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_us-gaap_SwaptionMember_B93C292898BB70F110B492D56D9A1F02" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_AECC72A4EB26FB1644D792D56D9AC849" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_us-gaap_InterestRateSwapMember_AECC72A4EB26FB1644D792D56D9AC849" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherDerivativesMember" xlink:label="loc_agnc_OtherDerivativesMember_E7F01EB5494D60D7253492D56D9A7285" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_agnc_OtherDerivativesMember_E7F01EB5494D60D7253492D56D9A7285" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TBAandForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_1BE0BE3129E8F5FBA5C392D56D9A3A57" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_agnc_TBAandForwardSettlingAgencySecuritiesMember_1BE0BE3129E8F5FBA5C392D56D9A3A57" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember" xlink:label="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_16DD57EA2ABC8AE6201E92D56D9A8E61" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_agnc_SaleOfTbaAndForwardSettlingAgencySecuritiesMember_16DD57EA2ABC8AE6201E92D56D9A8E61" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TreasuryFuturesMember" xlink:label="loc_agnc_TreasuryFuturesMember_D92238CFADC1F0EF8ACD92D56D9AD46B" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_agnc_TreasuryFuturesMember_D92238CFADC1F0EF8ACD92D56D9AD46B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_5D15BCBF141F617CD75192D56D9A9780" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_E70620333FB640CC6D5092D56D9AF904" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_5D15BCBF141F617CD75192D56D9A9780" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_32909FD9D83A2800BA4292D56D9AC3A2" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0ED32DF5388AAB21C95992D56D933288" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_32909FD9D83A2800BA4292D56D9AC3A2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_32909FD9D83A2800BA4292D56D9AC3A2" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_32909FD9D83A2800BA4292D56D9AC3A2" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TreasuryFuturesMember" xlink:label="loc_agnc_TreasuryFuturesMember_67B9BEA7AE70C08B4C1092D56D9A15E6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204" xlink:to="loc_agnc_TreasuryFuturesMember_67B9BEA7AE70C08B4C1092D56D9A15E6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_10D0AEE41E4DCD3F659292D56D9A9B44" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204" xlink:to="loc_us-gaap_InterestRateSwapMember_10D0AEE41E4DCD3F659292D56D9A9B44" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherDerivativesMember" xlink:label="loc_agnc_OtherDerivativesMember_4FA92E60B5F8FB44D3AE92D56D9A9883" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_DA2142CFD63642E1C60292D56D9AD204" xlink:to="loc_agnc_OtherDerivativesMember_4FA92E60B5F8FB44D3AE92D56D9A9883" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue" xlink:label="loc_us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue_55622BADB36B9F93F25092D56D9BFC75" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue_55622BADB36B9F93F25092D56D9BFC75" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets" xlink:label="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_05582FCED627808C9AD0932F85F36B62" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_05582FCED627808C9AD0932F85F36B62" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue" xlink:label="loc_us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue_293E594184657023988C92D56D9BEB86" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue_293E594184657023988C92D56D9BEB86" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_6276FDE99251C5E7FC1292D56D9BFA64" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_DerivativeAssets_6276FDE99251C5E7FC1292D56D9BFA64" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_DEB63FFDFC08A5E3B86392D56D9BFF0C" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_DEB63FFDFC08A5E3B86392D56D9BFF0C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLongTermDebt" xlink:label="loc_us-gaap_OtherLongTermDebt_70B8371041A03113ECF092D56D9B5C7B" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_OtherLongTermDebt_70B8371041A03113ECF092D56D9B5C7B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_BA1DE2EDD0E0B525F10292D56D9B0345" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_BA1DE2EDD0E0B525F10292D56D9B0345" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_6B1A9C9349D3DF05EDCC92D56D9B13C9" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue_6B1A9C9349D3DF05EDCC92D56D9B13C9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesEquitySecurities" xlink:label="loc_us-gaap_MarketableSecuritiesEquitySecurities_7C73978D8296EDDDA26D92D56D9BDEB5" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_MarketableSecuritiesEquitySecurities_7C73978D8296EDDDA26D92D56D9BDEB5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_92168ED396462DB24ECF92D56D9BC7A0" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue_92168ED396462DB24ECF92D56D9BC7A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_C700F12E7877D0328A9A92D56D9B3FC0" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_DerivativeLiabilities_C700F12E7877D0328A9A92D56D9B3FC0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_FF1543821C761F51707392D56D9B54B0" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_FF1543821C761F51707392D56D9B54B0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TransfersBetweenHierarchyLevels" xlink:label="loc_agnc_TransfersBetweenHierarchyLevels_9E5AD654A1318C608BA092D56D9B26EB" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_D967EE1E1ED5B3C90C8292D56D9BC4F8" xlink:to="loc_agnc_TransfersBetweenHierarchyLevels_9E5AD654A1318C608BA092D56D9B26EB" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/FairValueMeasurementsTables" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_C4F8C3C4D1851A383392F0C8A50A4C4C" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_A95AF9C2ACF8CD3F63C4F0C8A50A2DED" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_C4F8C3C4D1851A383392F0C8A50A4C4C" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_A95AF9C2ACF8CD3F63C4F0C8A50A2DED" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_697FB8E9EFDE25A2804FF0C8A50A2A2D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_A95AF9C2ACF8CD3F63C4F0C8A50A2DED" xlink:to="loc_us-gaap_HedgingDesignationAxis_697FB8E9EFDE25A2804FF0C8A50A2A2D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_899F67D0DC9A4A0BE66BF0C8A50A64E1_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_697FB8E9EFDE25A2804FF0C8A50A2A2D" xlink:to="loc_us-gaap_HedgingDesignationDomain_899F67D0DC9A4A0BE66BF0C8A50A64E1_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_899F67D0DC9A4A0BE66BF0C8A50A64E1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_697FB8E9EFDE25A2804FF0C8A50A2A2D" xlink:to="loc_us-gaap_HedgingDesignationDomain_899F67D0DC9A4A0BE66BF0C8A50A64E1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_1B4F6A6078A4A4A730F6F0C8A50A90D4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_899F67D0DC9A4A0BE66BF0C8A50A64E1" xlink:to="loc_us-gaap_NondesignatedMember_1B4F6A6078A4A4A730F6F0C8A50A90D4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_6E457AA6BFA7152EF5CCF0C8A50B70A3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_C4F8C3C4D1851A383392F0C8A50A4C4C" xlink:to="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_6E457AA6BFA7152EF5CCF0C8A50B70A3" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/IncomeTaxes" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExaminationLineItems" xlink:label="loc_us-gaap_IncomeTaxExaminationLineItems_DDC9A8432B1D2056624EF0C8A4D8B860" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExaminationTable" xlink:label="loc_us-gaap_IncomeTaxExaminationTable_E6887CCAAB96903835ADF0C8A4D8F3A6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_DDC9A8432B1D2056624EF0C8A4D8B860" xlink:to="loc_us-gaap_IncomeTaxExaminationTable_E6887CCAAB96903835ADF0C8A4D8F3A6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_88037777450320B85AE8F0C8A4D85DD4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_E6887CCAAB96903835ADF0C8A4D8F3A6" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_88037777450320B85AE8F0C8A4D85DD4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_AB2C05A59A68D34BF5EEF0C8A4D868C6_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_88037777450320B85AE8F0C8A4D85DD4" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_AB2C05A59A68D34BF5EEF0C8A4D868C6_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_AB2C05A59A68D34BF5EEF0C8A4D868C6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_88037777450320B85AE8F0C8A4D85DD4" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_AB2C05A59A68D34BF5EEF0C8A4D868C6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_544AF8C7B006EC7A1C6EF0C8A4D8C5A0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_E6887CCAAB96903835ADF0C8A4D8F3A6" xlink:to="loc_us-gaap_RangeAxis_544AF8C7B006EC7A1C6EF0C8A4D8C5A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_F0C0609B0461356CAC1DF0C8A4D8BA2B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_544AF8C7B006EC7A1C6EF0C8A4D8C5A0" xlink:to="loc_us-gaap_RangeMember_F0C0609B0461356CAC1DF0C8A4D8BA2B_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_F0C0609B0461356CAC1DF0C8A4D8BA2B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_544AF8C7B006EC7A1C6EF0C8A4D8C5A0" xlink:to="loc_us-gaap_RangeMember_F0C0609B0461356CAC1DF0C8A4D8BA2B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock_BAFCB4EEB4CE8884FCDCF0C8A4D8FD0D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_DDC9A8432B1D2056624EF0C8A4D8B860" xlink:to="loc_us-gaap_IncomeTaxDisclosureTextBlock_BAFCB4EEB4CE8884FCDCF0C8A4D8FD0D" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/IncomeTaxesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems" xlink:label="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FederalIncomeTaxNoteTable" xlink:label="loc_us-gaap_FederalIncomeTaxNoteTable_8A6A28E6412DEE0943F8F0C8A4B7A129" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_FederalIncomeTaxNoteTable_8A6A28E6412DEE0943F8F0C8A4B7A129" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationAxis" xlink:label="loc_agnc_TaxCharacterizationAxis_9D1F3AECDAEA7D1F7447F0C8A4B7C485" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FederalIncomeTaxNoteTable_8A6A28E6412DEE0943F8F0C8A4B7A129" xlink:to="loc_agnc_TaxCharacterizationAxis_9D1F3AECDAEA7D1F7447F0C8A4B7C485" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationDomain" xlink:label="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_TaxCharacterizationAxis_9D1F3AECDAEA7D1F7447F0C8A4B7C485" xlink:to="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationDomain" xlink:label="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_TaxCharacterizationAxis_9D1F3AECDAEA7D1F7447F0C8A4B7C485" xlink:to="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_QualifiedDividendsPerShareMember" xlink:label="loc_agnc_QualifiedDividendsPerShareMember_6475C07292D0B34FCB9FF0C8A4B77852" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC" xlink:to="loc_agnc_QualifiedDividendsPerShareMember_6475C07292D0B34FCB9FF0C8A4B77852" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OrdinaryIncomePerShareMember" xlink:label="loc_agnc_OrdinaryIncomePerShareMember_6D3595DDE3E069F9BA75F0C8A4B7828F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC" xlink:to="loc_agnc_OrdinaryIncomePerShareMember_6D3595DDE3E069F9BA75F0C8A4B7828F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LongtermCapitalGainMember" xlink:label="loc_agnc_LongtermCapitalGainMember_C52633B8506305BC7598F0C8A4B79385" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CBB75B31FA67EB0B269BF0C8A4B7D6BC" xlink:to="loc_agnc_LongtermCapitalGainMember_C52633B8506305BC7598F0C8A4B79385" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockDividendRatePerDollarAmount" xlink:label="loc_us-gaap_PreferredStockDividendRatePerDollarAmount_5A4B09F27AC1E0E0494BF0C8A4B77965" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_PreferredStockDividendRatePerDollarAmount_5A4B09F27AC1E0E0494BF0C8A4B77965" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsPreferredStock" xlink:label="loc_us-gaap_DividendsPreferredStock_3ECA321C2802AA5BEBDEF0C8A4B71C9D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_DividendsPreferredStock_3ECA321C2802AA5BEBDEF0C8A4B71C9D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UndistributedTaxableIncome" xlink:label="loc_agnc_UndistributedTaxableIncome_1E91D3389F87C84EFD38F0C8A4B720D0" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_agnc_UndistributedTaxableIncome_1E91D3389F87C84EFD38F0C8A4B720D0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ExciseAndSalesTaxes" xlink:label="loc_us-gaap_ExciseAndSalesTaxes_3A227E7B87D855C5A2D7F0C8A4B743B5" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_ExciseAndSalesTaxes_3A227E7B87D855C5A2D7F0C8A4B743B5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_163DEDD0908145517B17F0C8A4B72A0C" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_163DEDD0908145517B17F0C8A4B72A0C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_B0D8C533576959D1FCDFF0C8A4B7D00D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_B0D8C533576959D1FCDFF0C8A4B7D00D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_B496359613FDC1C1255FF0C8A4B76D59" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_B496359613FDC1C1255FF0C8A4B76D59" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsCommonStock" xlink:label="loc_us-gaap_DividendsCommonStock_7DDC159449D7FBA8C62DF0C8A4B728D8" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_DividendsCommonStock_7DDC159449D7FBA8C62DF0C8A4B728D8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_2053BA10504EE01993D9F0C8A4B7CBEF" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsOwnedFederalIncomeTaxNoteLineItems_30ECEEA51426BF2F4CA8F0C8A4B7A30D" xlink:to="loc_us-gaap_DividendsCommonStockCash_2053BA10504EE01993D9F0C8A4B7CBEF" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/IncomeTaxesTables" xlink:type="extended">
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleofDividendsPaidLineItems" xlink:label="loc_agnc_ScheduleofDividendsPaidLineItems_2FF2E106048E2B6CFE55F0C8A4CE6ED6" xlink:type="locator" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleofDividendsPaidTable" xlink:label="loc_agnc_ScheduleofDividendsPaidTable_F0A3B7170A5909F1E495F0C8A4CEA346" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_agnc_ScheduleofDividendsPaidLineItems_2FF2E106048E2B6CFE55F0C8A4CE6ED6" xlink:to="loc_agnc_ScheduleofDividendsPaidTable_F0A3B7170A5909F1E495F0C8A4CEA346" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationAxis" xlink:label="loc_agnc_TaxCharacterizationAxis_A578C873FCA0A4FBD539F0C8A4CE5435" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_ScheduleofDividendsPaidTable_F0A3B7170A5909F1E495F0C8A4CEA346" xlink:to="loc_agnc_TaxCharacterizationAxis_A578C873FCA0A4FBD539F0C8A4CE5435" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationDomain" xlink:label="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_TaxCharacterizationAxis_A578C873FCA0A4FBD539F0C8A4CE5435" xlink:to="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TaxCharacterizationDomain" xlink:label="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_TaxCharacterizationAxis_A578C873FCA0A4FBD539F0C8A4CE5435" xlink:to="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_QualifiedDividendsPerShareMember" xlink:label="loc_agnc_QualifiedDividendsPerShareMember_C9AC9514BA411EF3B11BF0C8A4CE6C3F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33" xlink:to="loc_agnc_QualifiedDividendsPerShareMember_C9AC9514BA411EF3B11BF0C8A4CE6C3F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OrdinaryIncomePerShareMember" xlink:label="loc_agnc_OrdinaryIncomePerShareMember_B515C81B1D64D4EB4842F0C8A4CE5377" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33" xlink:to="loc_agnc_OrdinaryIncomePerShareMember_B515C81B1D64D4EB4842F0C8A4CE5377" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LongtermCapitalGainMember" xlink:label="loc_agnc_LongtermCapitalGainMember_217EF10176F4B69BE9DAF0C8A4CE315A" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_TaxCharacterizationDomain_CED749F12766D2BC23EBF0C8A4CE2A33" xlink:to="loc_agnc_LongtermCapitalGainMember_217EF10176F4B69BE9DAF0C8A4CE315A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DividendsDeclaredTableTextBlock" xlink:label="loc_us-gaap_DividendsDeclaredTableTextBlock_CDEA71A4B1DC2E70F8B6F0C8A4CE2FE1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_ScheduleofDividendsPaidLineItems_2FF2E106048E2B6CFE55F0C8A4CE6ED6" xlink:to="loc_us-gaap_DividendsDeclaredTableTextBlock_CDEA71A4B1DC2E70F8B6F0C8A4CE2FE1" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecurities" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesComponentsOfInvestmentSecuritiesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_E86B12E999984822F67EF0C8A4E6C3FE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_E86B12E999984822F67EF0C8A4E6C3FE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_6DB30361FAB5B35FD81CF0C8A4E6F3C5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_E86B12E999984822F67EF0C8A4E6C3FE" xlink:to="loc_us-gaap_InvestmentTypeAxis_6DB30361FAB5B35FD81CF0C8A4E6F3C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_A421B91CDE582BA7E61AF0C8A4E6E80D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_6DB30361FAB5B35FD81CF0C8A4E6F3C5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_A421B91CDE582BA7E61AF0C8A4E6E80D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_A421B91CDE582BA7E61AF0C8A4E6E80D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_6DB30361FAB5B35FD81CF0C8A4E6F3C5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_A421B91CDE582BA7E61AF0C8A4E6E80D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_FB68E0817F0AA7C547BCF0C8A4E7A3CD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_A421B91CDE582BA7E61AF0C8A4E6E80D" xlink:to="loc_us-gaap_AgencySecuritiesMember_FB68E0817F0AA7C547BCF0C8A4E7A3CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_55A90E500AC0483E115AF0C8A4E7E9A0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_E86B12E999984822F67EF0C8A4E6C3FE" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_55A90E500AC0483E115AF0C8A4E7E9A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_55A90E500AC0483E115AF0C8A4E7E9A0" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_55A90E500AC0483E115AF0C8A4E7E9A0" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FixedIncomeSecuritiesMember" xlink:label="loc_us-gaap_FixedIncomeSecuritiesMember_B08E7F5933A9DB9FD603F0C8A4E745DF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:to="loc_us-gaap_FixedIncomeSecuritiesMember_B08E7F5933A9DB9FD603F0C8A4E745DF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustableRateLoansMember" xlink:label="loc_us-gaap_AdjustableRateLoansMember_C510AD46E4672955490DF0C8A4E7E2E2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:to="loc_us-gaap_AdjustableRateLoansMember_C510AD46E4672955490DF0C8A4E7E2E2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CollateralizedMortgageObligationsMember" xlink:label="loc_us-gaap_CollateralizedMortgageObligationsMember_F09847E759585E5156B4F0C8A4E72B97" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:to="loc_us-gaap_CollateralizedMortgageObligationsMember_F09847E759585E5156B4F0C8A4E72B97" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_2A759AB412585170E9B5F0C8A4E7457D" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_1D9A533F59FFEB29B79AF0C8A4E70A53" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_2A759AB412585170E9B5F0C8A4E7457D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesAmortizedCost" xlink:label="loc_agnc_AgencySecuritiesAmortizedCost_4F7C6E04BE4948D7FC47F0C8A4E7DCF9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_AgencySecuritiesAmortizedCost_4F7C6E04BE4948D7FC47F0C8A4E7DCF9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesGrossUnrealizedGain" xlink:label="loc_agnc_AgencySecuritiesGrossUnrealizedGain_EA0FAEE0ACC44905A7A5F0C8A4E7BD37" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_AgencySecuritiesGrossUnrealizedGain_EA0FAEE0ACC44905A7A5F0C8A4E7BD37" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesGrossUnrealizedLoss" xlink:label="loc_agnc_AgencySecuritiesGrossUnrealizedLoss_65C90F92C199565EE401F0C8A4E7E358" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_AgencySecuritiesGrossUnrealizedLoss_65C90F92C199565EE401F0C8A4E7E358" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_6C494E5DA7DC30DF4AECF0C8A4E71E21" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_us-gaap_AvailableForSaleSecurities_6C494E5DA7DC30DF4AECF0C8A4E71E21" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_060B461EAE058069A749F0C8A4E7FA2B" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_060B461EAE058069A749F0C8A4E7FA2B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalAgencySecurities" xlink:label="loc_agnc_TotalAgencySecurities_1CE1CD0014AE317CE52AF0C8A4E7FDDF" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_TotalAgencySecurities_1CE1CD0014AE317CE52AF0C8A4E7FDDF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateDerivativeAssetsAtAmortizedCost" xlink:label="loc_agnc_InterestRateDerivativeAssetsAtAmortizedCost_5685F384B7BE25787848F0C8A4E7AFAD" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_InterestRateDerivativeAssetsAtAmortizedCost_5685F384B7BE25787848F0C8A4E7AFAD" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnrealizedGainOnDerivatives" xlink:label="loc_agnc_UnrealizedGainOnDerivatives_BC62A1080E3C278D53ABF0C8A4E8ECA9" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_UnrealizedGainOnDerivatives_BC62A1080E3C278D53ABF0C8A4E8ECA9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnrealizedLossOnDerivatives" xlink:label="loc_agnc_UnrealizedLossOnDerivatives_94F746BA5F6128E32C3AF0C8A4E83351" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_agnc_UnrealizedLossOnDerivatives_94F746BA5F6128E32C3AF0C8A4E83351" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativeAssetsAtFairValue" xlink:label="loc_us-gaap_InterestRateDerivativeAssetsAtFairValue_833506530DB7A774D252F0C8A4E8AC8B" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D5318C7FDAD7C42D3011F0C8A4E7A2D0" xlink:to="loc_us-gaap_InterestRateDerivativeAssetsAtFairValue_833506530DB7A774D252F0C8A4E8AC8B" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesNarrativeDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_34865EF9081EF197029F92C3DEF63764" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_34865EF9081EF197029F92C3DEF63764" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_69C90F54C1EE348A6E8392C3DEF790F2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_34865EF9081EF197029F92C3DEF63764" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_69C90F54C1EE348A6E8392C3DEF790F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2980682F78B4CA4F051B92C3DEF7D467_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_69C90F54C1EE348A6E8392C3DEF790F2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2980682F78B4CA4F051B92C3DEF7D467_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2980682F78B4CA4F051B92C3DEF7D467" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_69C90F54C1EE348A6E8392C3DEF790F2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2980682F78B4CA4F051B92C3DEF7D467" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_B64ACE6D8507F627FA7992C3DEF72639" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_2980682F78B4CA4F051B92C3DEF7D467" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_B64ACE6D8507F627FA7992C3DEF72639" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_F5FA421FD884FDAF304692C3DEF75EFA" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_34865EF9081EF197029F92C3DEF63764" xlink:to="loc_us-gaap_InvestmentTypeAxis_F5FA421FD884FDAF304692C3DEF75EFA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_2CAF9FB6F04C3BD884EA92C3DEF7058A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_F5FA421FD884FDAF304692C3DEF75EFA" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_2CAF9FB6F04C3BD884EA92C3DEF7058A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_2CAF9FB6F04C3BD884EA92C3DEF7058A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_F5FA421FD884FDAF304692C3DEF75EFA" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_2CAF9FB6F04C3BD884EA92C3DEF7058A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_923FBEEDAA9E4216CB2A92C3DEF75B39" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_2CAF9FB6F04C3BD884EA92C3DEF7058A" xlink:to="loc_us-gaap_AgencySecuritiesMember_923FBEEDAA9E4216CB2A92C3DEF75B39" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_BDC640878C15C5996FFE92C3DEF7845C" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_34865EF9081EF197029F92C3DEF63764" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_BDC640878C15C5996FFE92C3DEF7845C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_0F767C280A4814DED8C892C3DEF72822_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_BDC640878C15C5996FFE92C3DEF7845C" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_0F767C280A4814DED8C892C3DEF72822_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_0F767C280A4814DED8C892C3DEF72822" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_BDC640878C15C5996FFE92C3DEF7845C" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_0F767C280A4814DED8C892C3DEF72822" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradingSecuritiesRealizedGainLoss" xlink:label="loc_us-gaap_TradingSecuritiesRealizedGainLoss_617B3A5AC8390BEE0D7292C3DEF873D8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_TradingSecuritiesRealizedGainLoss_617B3A5AC8390BEE0D7292C3DEF873D8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_A9DF68940CAF0E51784B92C3DEF84EB3" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_A9DF68940CAF0E51784B92C3DEF84EB3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GainLossOnOtherDebt" xlink:label="loc_agnc_GainLossOnOtherDebt_916AE5BE2CC7355F7EC392C3DEF84FE7" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_GainLossOnOtherDebt_916AE5BE2CC7355F7EC392C3DEF84FE7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio" xlink:label="loc_agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio_99071A30A017428D79CB92C3DEF8291C" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio_99071A30A017428D79CB92C3DEF8291C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfInterestOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_7843E18577DB0763DFFE92C3DEF8C39A" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_7843E18577DB0763DFFE92C3DEF8C39A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfPrincipalOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_06B94EB986AE60D7B9D692C3DEF8FD08" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_06B94EB986AE60D7B9D692C3DEF8FD08" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_FairValueOfCmoSecuritiesDirectlyHeld" xlink:label="loc_agnc_FairValueOfCmoSecuritiesDirectlyHeld_AAF32497489E8506842992C3DEF824E1" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_FairValueOfCmoSecuritiesDirectlyHeld_AAF32497489E8506842992C3DEF824E1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SecuritizedCmoSecurities" xlink:label="loc_agnc_SecuritizedCmoSecurities_11E8CA39FF20780E173892C3DEF82481" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_SecuritizedCmoSecurities_11E8CA39FF20780E173892C3DEF82481" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_CmoAndInterestOnlyPricincipalOnlySecuritiesMaximumLossExposure" xlink:label="loc_agnc_CmoAndInterestOnlyPricincipalOnlySecuritiesMaximumLossExposure_3E43A3D5F2FF446BB9A892C3DEF8D6FA" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_CmoAndInterestOnlyPricincipalOnlySecuritiesMaximumLossExposure_3E43A3D5F2FF446BB9A892C3DEF8D6FA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecuritiesHeldAsCollateralAtFairValue" xlink:label="loc_us-gaap_SecuritiesHeldAsCollateralAtFairValue_35B91CCEA8065F0F4BC592C3DEF8C6C5" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_SecuritiesHeldAsCollateralAtFairValue_35B91CCEA8065F0F4BC592C3DEF8C6C5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PrincipalBalanceOfSecuritiesHeldAsCollateral" xlink:label="loc_agnc_PrincipalBalanceOfSecuritiesHeldAsCollateral_A93196E196F4AB0CAAA492C3DEF84B23" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_agnc_PrincipalBalanceOfSecuritiesHeldAsCollateral_A93196E196F4AB0CAAA492C3DEF84B23" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_61CA851FAEB62822EAED92C3DEF8484B" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_61CA851FAEB62822EAED92C3DEF8484B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLongTermDebt" xlink:label="loc_us-gaap_OtherLongTermDebt_4003EB78A5A926438FE992C3DEF8FE2F" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_F5A3D0215C5FC6FF760392C3DEF716F5" xlink:to="loc_us-gaap_OtherLongTermDebt_4003EB78A5A926438FE992C3DEF8FE2F" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfAgencySecuritiesEstimatedWeightedAverageLifeClassificationsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_CE06D2EDD4E08B60A028F0C8A46F4B5F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_CE06D2EDD4E08B60A028F0C8A46F4B5F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_77875A5E023EDE0BDF3EF0C8A46F928B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_CE06D2EDD4E08B60A028F0C8A46F4B5F" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_77875A5E023EDE0BDF3EF0C8A46F928B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_77875A5E023EDE0BDF3EF0C8A46F928B" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_77875A5E023EDE0BDF3EF0C8A46F928B" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_LessThanOrEqualToOneYearMember" xlink:label="loc_agnc_LessThanOrEqualToOneYearMember_5E34DC3CA120B451831FF0C8A46FE458" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:to="loc_agnc_LessThanOrEqualToOneYearMember_5E34DC3CA120B451831FF0C8A46FE458" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember" xlink:label="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_E9960B89F1A0F9FC76EDF0C8A46FE6F0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:to="loc_agnc_GreaterThanOneYearAndLessThanOrEqualToThreeYearsMember_E9960B89F1A0F9FC76EDF0C8A46FE6F0" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember" xlink:label="loc_agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember_8F3749DC7316EE29180FF0C8A46FC7F2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:to="loc_agnc_GreaterThanThreeYearsAndLessThanOrEqualToFiveYearsMember_8F3749DC7316EE29180FF0C8A46FC7F2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanFiveYearsMember" xlink:label="loc_agnc_GreaterThanFiveYearsMember_4F9DD279CC79A18E8C49F0C8A46FE336" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:to="loc_agnc_GreaterThanFiveYearsMember_4F9DD279CC79A18E8C49F0C8A46FE336" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GreaterThanTenYearsMember" xlink:label="loc_agnc_GreaterThanTenYearsMember_23AFC1956071DE54F116F0C8A470A783" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_55705E986B7ED93B1208F0C8A46FE32A" xlink:to="loc_agnc_GreaterThanTenYearsMember_23AFC1956071DE54F116F0C8A470A783" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfInterestOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_CD9AA9E9702D9300A85EF0C8A47002F8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_CD9AA9E9702D9300A85EF0C8A47002F8" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeInterestOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeInterestOnlySecurities_5DD0E25CC0F0F903E1C2F0C8A47090C2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_WeightedAverageLifeInterestOnlySecurities_5DD0E25CC0F0F903E1C2F0C8A47090C2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifePrincipalOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifePrincipalOnlySecurities_CFE8BD19B505B5DA887AF0C8A47012DC" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_WeightedAverageLifePrincipalOnlySecurities_CFE8BD19B505B5DA887AF0C8A47012DC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesWeightedAverageLifeFairValue" xlink:label="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeFairValue_7238537DB6AD5BE99D82F0C8A470E66B" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeFairValue_7238537DB6AD5BE99D82F0C8A470E66B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesWeightedAverageLifeAmortizedCost" xlink:label="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeAmortizedCost_3F511C16875831849A0FF0C8A470D339" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeAmortizedCost_3F511C16875831849A0FF0C8A470D339" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_8F6E85367367CBEA7117F0C8A470A807" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_us-gaap_AvailableForSaleSecurities_8F6E85367367CBEA7117F0C8A470A807" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_2597C1B70F8765F6AA48F0C8A4704ABB" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_2597C1B70F8765F6AA48F0C8A4704ABB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesWeightedAverageLifeCouponRate" xlink:label="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeCouponRate_1418436F5204D26B500AF0C8A4700BB2" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeCouponRate_1418436F5204D26B500AF0C8A4700BB2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesWeightedAverageLifeYield" xlink:label="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeYield_1A4E8E0D3D5FB9E11474F0C8A47092A7" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_AvailableForSaleSecuritiesWeightedAverageLifeYield_1A4E8E0D3D5FB9E11474F0C8A47092A7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfPrincipalOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_9688E7766393766499F0F0C8A4702FCD" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_999223991B5262795B48F0C8A470D782" xlink:to="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_9688E7766393766499F0F0C8A4702FCD" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfChangesInAccumulatedOciForAvailableForSaleSecurityDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_5C43BDEFB418369E9D244DE9EFB73C06" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2DD3753F08D1BBA78F224DE9EFB66F88" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_5C43BDEFB418369E9D244DE9EFB73C06" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2DD3753F08D1BBA78F224DE9EFB66F88" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_8DEF00C30168DD1AB8614DE9EFB6156D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2DD3753F08D1BBA78F224DE9EFB66F88" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_8DEF00C30168DD1AB8614DE9EFB6156D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_5F14AB6EBC250D2C9AE14DE9EFB62248_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_8DEF00C30168DD1AB8614DE9EFB6156D" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_5F14AB6EBC250D2C9AE14DE9EFB62248_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_5F14AB6EBC250D2C9AE14DE9EFB62248" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_8DEF00C30168DD1AB8614DE9EFB6156D" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_5F14AB6EBC250D2C9AE14DE9EFB62248" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_CD5A7F715FAC0D0387E24DE9EFB67123" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_5F14AB6EBC250D2C9AE14DE9EFB62248" xlink:to="loc_us-gaap_AgencySecuritiesMember_CD5A7F715FAC0D0387E24DE9EFB67123" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AccumulatedOtherComprehensiveIncomeLossRollForward" xlink:label="loc_agnc_AccumulatedOtherComprehensiveIncomeLossRollForward_2D3CC36C5FD4DA378D8B4DE9EFB75C87" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5C43BDEFB418369E9D244DE9EFB73C06" xlink:to="loc_agnc_AccumulatedOtherComprehensiveIncomeLossRollForward_2D3CC36C5FD4DA378D8B4DE9EFB75C87" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_41885CCC108CA190C30C4DE9EFB7875A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_AccumulatedOtherComprehensiveIncomeLossRollForward_2D3CC36C5FD4DA378D8B4DE9EFB75C87" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_41885CCC108CA190C30C4DE9EFB7875A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_1F7B742222AE124C672E4DE9EFB7FC12" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_AccumulatedOtherComprehensiveIncomeLossRollForward_2D3CC36C5FD4DA378D8B4DE9EFB75C87" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_1F7B742222AE124C672E4DE9EFB7FC12" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization" xlink:label="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_0172957906B3202AB34A4DE9EFB704E4" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_AccumulatedOtherComprehensiveIncomeLossRollForward_2D3CC36C5FD4DA378D8B4DE9EFB75C87" xlink:to="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_0172957906B3202AB34A4DE9EFB704E4" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfContinuousUnrealizedLossPositionsOfAvailableForSaleSecurityDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_3E04C9E201C71461704FF0C8A4EBFC9B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_StatementTable_3E04C9E201C71461704FF0C8A4EBFC9B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_DAC2975C31D3488CA048F0C8A4EB8DE0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_3E04C9E201C71461704FF0C8A4EBFC9B" xlink:to="loc_dei_LegalEntityAxis_DAC2975C31D3488CA048F0C8A4EB8DE0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_A56661D0E9356D57F9A8F0C8A4EB9838_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_DAC2975C31D3488CA048F0C8A4EB8DE0" xlink:to="loc_dei_EntityDomain_A56661D0E9356D57F9A8F0C8A4EB9838_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_A56661D0E9356D57F9A8F0C8A4EB9838" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_DAC2975C31D3488CA048F0C8A4EB8DE0" xlink:to="loc_dei_EntityDomain_A56661D0E9356D57F9A8F0C8A4EB9838" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8A89010D778F1E40DD13F0C8A4EB84EE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_A56661D0E9356D57F9A8F0C8A4EB9838" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8A89010D778F1E40DD13F0C8A4EB84EE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_CD93D6861230FE5F2911F0C8A4EB8FD5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_CD93D6861230FE5F2911F0C8A4EB8FD5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses_3202648299DF81AF6DB4F0C8A4EBF87D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses_3202648299DF81AF6DB4F0C8A4EBF87D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_D5393F99B388689B038CF0C8A4EB2CE1" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_D5393F99B388689B038CF0C8A4EB2CE1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses_7221D8B1E82357E7834DF0C8A4ECA77C" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses_7221D8B1E82357E7834DF0C8A4ECA77C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_E746B17C13B1947ED914F0C8A4EC7FEE" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_E746B17C13B1947ED914F0C8A4EC7FEE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses_F7B372B058FE326217FDF0C8A4EC63D7" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4EBD141380CE5BDF5433F0C8A4EB902A" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses_F7B372B058FE326217FDF0C8A4EC63D7" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfInvestmentInAgencySecurityDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_3C0AB27A87C3692E8C14F0C8A49B9CE3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_3C0AB27A87C3692E8C14F0C8A49B9CE3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_85F3BA87FC1950CF43DFF0C8A49B1868_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_3C0AB27A87C3692E8C14F0C8A49B9CE3" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_85F3BA87FC1950CF43DFF0C8A49B1868_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_85F3BA87FC1950CF43DFF0C8A49B1868" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_3C0AB27A87C3692E8C14F0C8A49B9CE3" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_85F3BA87FC1950CF43DFF0C8A49B1868" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_C9DFCB54E006A0DBE3A1F0C8A49B155D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_85F3BA87FC1950CF43DFF0C8A49B1868" xlink:to="loc_us-gaap_DerivativeMember_C9DFCB54E006A0DBE3A1F0C8A49B155D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_ED6DB5CD13F663D3E11AF0C8A49BF7EC" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_us-gaap_InvestmentTypeAxis_ED6DB5CD13F663D3E11AF0C8A49BF7EC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1F593A42355401618A8CF0C8A49B0D3F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_ED6DB5CD13F663D3E11AF0C8A49BF7EC" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1F593A42355401618A8CF0C8A49B0D3F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1F593A42355401618A8CF0C8A49B0D3F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_ED6DB5CD13F663D3E11AF0C8A49BF7EC" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1F593A42355401618A8CF0C8A49B0D3F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_FE7C6BB33E1E1941D786F0C8A49B4203" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1F593A42355401618A8CF0C8A49B0D3F" xlink:to="loc_us-gaap_DerivativeMember_FE7C6BB33E1E1941D786F0C8A49B4203" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtSecurityAxis" xlink:label="loc_us-gaap_DebtSecurityAxis_2862AC4CE26C438C8883F0C8A49B8B94" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_us-gaap_DebtSecurityAxis_2862AC4CE26C438C8883F0C8A49B8B94" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_33A793697098663B0C90F0C8A49B4A78_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtSecurityAxis_2862AC4CE26C438C8883F0C8A49B8B94" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_33A793697098663B0C90F0C8A49B4A78_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_33A793697098663B0C90F0C8A49B4A78" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtSecurityAxis_2862AC4CE26C438C8883F0C8A49B8B94" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_33A793697098663B0C90F0C8A49B4A78" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AssetsPledgedtoUsMember" xlink:label="loc_agnc_AssetsPledgedtoUsMember_0C9F851173D22C17D2B2F0C8A49BDC3E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_33A793697098663B0C90F0C8A49B4A78" xlink:to="loc_agnc_AssetsPledgedtoUsMember_0C9F851173D22C17D2B2F0C8A49BDC3E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassAxis" xlink:label="loc_invest_InvestmentSecuritiesClassAxis_F163683AF53A99DA6F45F0C8A49B9E42" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_invest_InvestmentSecuritiesClassAxis_F163683AF53A99DA6F45F0C8A49B9E42" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_F163683AF53A99DA6F45F0C8A49B9E42" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_F163683AF53A99DA6F45F0C8A49B9E42" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_9BB66DEB491112AD4A80F0C8A49CD4F0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C" xlink:to="loc_us-gaap_DerivativeMember_9BB66DEB491112AD4A80F0C8A49CD4F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_EC79A57025871E55BADBF0C8A49C063A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_B7675B0D811844E4ED27F0C8A49B8C0C" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_EC79A57025871E55BADBF0C8A49C063A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EligibleItemOrGroupForFairValueOptionAxis" xlink:label="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_4D95AD84FB1C633BDFB0F0C8A49C4C29" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_4D95AD84FB1C633BDFB0F0C8A49C4C29" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueOptionEligibleItemOrGroupDomain" xlink:label="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_4D95AD84FB1C633BDFB0F0C8A49C4C29" xlink:to="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueOptionEligibleItemOrGroupDomain" xlink:label="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_4D95AD84FB1C633BDFB0F0C8A49C4C29" xlink:to="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableforsaleSecuritiesMember" xlink:label="loc_us-gaap_AvailableforsaleSecuritiesMember_9B67804C0608E3E2E89FF0C8A49C915E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C" xlink:to="loc_us-gaap_AvailableforsaleSecuritiesMember_9B67804C0608E3E2E89FF0C8A49C915E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesRemeasuredAtFairValueThroughEarningsMember" xlink:label="loc_agnc_AgencySecuritiesRemeasuredAtFairValueThroughEarningsMember_D54D8FF2059D4BD75762F0C8A49C5865" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_E079AD7104FA24564CD0F0C8A49CC93C" xlink:to="loc_agnc_AgencySecuritiesRemeasuredAtFairValueThroughEarningsMember_D54D8FF2059D4BD75762F0C8A49C5865" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_3237A74B17B9582BE4EDF0C8A49C6233" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_2D7154744D4E40BCDB94F0C8A49B8F34" xlink:to="loc_dei_LegalEntityAxis_3237A74B17B9582BE4EDF0C8A49C6233" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_3237A74B17B9582BE4EDF0C8A49C6233" xlink:to="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_3237A74B17B9582BE4EDF0C8A49C6233" xlink:to="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember" xlink:label="loc_us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember_30401A0A203BD11B464AF0C8A49CF6E0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87" xlink:to="loc_us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember_30401A0A203BD11B464AF0C8A49CF6E0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember" xlink:label="loc_us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember_28A21BADA7BBBB013690F0C8A49C4D9C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87" xlink:to="loc_us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember_28A21BADA7BBBB013690F0C8A49C4D9C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember" xlink:label="loc_us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember_162DC3C9061F6ED0AF3CF0C8A49C67B9" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_7E88AAE83162A92BA080F0C8A49C5E87" xlink:to="loc_us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember_162DC3C9061F6ED0AF3CF0C8A49C67B9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_7D55BD8B1317F4DED7F3F0C8A49C5CEF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_7D55BD8B1317F4DED7F3F0C8A49C5CEF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfInterestOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_AB06670EA1752A89AFEDF0C8A49C4736" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_WeightedAverageLifeOfInterestOnlySecurities_AB06670EA1752A89AFEDF0C8A49C4736" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesPar" xlink:label="loc_agnc_AvailableForSaleSecuritiesPar_F4221729B9ABA3FD2A63F0C8A49C9977" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_AvailableForSaleSecuritiesPar_F4221729B9ABA3FD2A63F0C8A49C9977" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_FF3CB0EDF6ED5165CD74F0C8A49C9354" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_FF3CB0EDF6ED5165CD74F0C8A49C9354" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentUnamortizedPremium" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium_055ACCBE49C269E7FC6CF0C8A49D55C0" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedPremium_055ACCBE49C269E7FC6CF0C8A49D55C0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_0F7CD27400AE299A678FF0C8A49D866A" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_0F7CD27400AE299A678FF0C8A49D866A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains_CF972BF687265AF524E4F0C8A49DD89F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains_CF972BF687265AF524E4F0C8A49DD89F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss_218D3A26600AF4812EBEF0C8A49D093D" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss_218D3A26600AF4812EBEF0C8A49D093D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_1A2AF10820FC64307E5BF0C8A49DF26D" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_1A2AF10820FC64307E5BF0C8A49DF26D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateDerivativeAssetsAtAmortizedCost" xlink:label="loc_agnc_InterestRateDerivativeAssetsAtAmortizedCost_93742F45C466D0E1E873F0C8A49D693D" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_InterestRateDerivativeAssetsAtAmortizedCost_93742F45C466D0E1E873F0C8A49D693D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnrealizedGainOnDerivatives" xlink:label="loc_agnc_UnrealizedGainOnDerivatives_4BA43652BB9BF620C074F0C8A49DCB4C" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_UnrealizedGainOnDerivatives_4BA43652BB9BF620C074F0C8A49DCB4C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnrealizedLossOnDerivatives" xlink:label="loc_agnc_UnrealizedLossOnDerivatives_92A1CBD5B903C538C338F0C8A49D98EB" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_UnrealizedLossOnDerivatives_92A1CBD5B903C538C338F0C8A49D98EB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateDerivativeAssetsAtFairValue" xlink:label="loc_us-gaap_InterestRateDerivativeAssetsAtFairValue_F94ED44566ECA17740A6F0C8A49DF92E" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_InterestRateDerivativeAssetsAtFairValue_F94ED44566ECA17740A6F0C8A49DF92E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalAgencySecurities" xlink:label="loc_agnc_TotalAgencySecurities_E38CD15D156C29FFDE72F0C8A49D69FE" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_TotalAgencySecurities_E38CD15D156C29FFDE72F0C8A49D69FE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtWeightedAverageInterestRate" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_581E237487D65AE07CF5F0C8A49DA2B1" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_581E237487D65AE07CF5F0C8A49DA2B1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageYieldPercentage" xlink:label="loc_agnc_WeightedAverageYieldPercentage_EDF0B2E5A603DF0A8533F0C8A49DDF3E" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_WeightedAverageYieldPercentage_EDF0B2E5A603DF0A8533F0C8A49DDF3E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageYieldPercentageForPeriod" xlink:label="loc_agnc_WeightedAverageYieldPercentageForPeriod_DEC97D301FC9445D930FF0C8A49D4A55" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_WeightedAverageYieldPercentageForPeriod_DEC97D301FC9445D930FF0C8A49D4A55" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnamortizedPrincipalBalanceOfInterestOnlyStrips" xlink:label="loc_agnc_UnamortizedPrincipalBalanceOfInterestOnlyStrips_762055C064757E753B06F0C8A49D6D38" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_UnamortizedPrincipalBalanceOfInterestOnlyStrips_762055C064757E753B06F0C8A49D6D38" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnamortizedPrincipalBalanceOfPrincipalOnlyStrips" xlink:label="loc_agnc_UnamortizedPrincipalBalanceOfPrincipalOnlyStrips_F62B351BA15437AF38A4F0C8A49D7D48" xlink:type="locator" />
    <definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_UnamortizedPrincipalBalanceOfPrincipalOnlyStrips_F62B351BA15437AF38A4F0C8A49D7D48" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageContractualInterestRateOfInterestOnlyStrips" xlink:label="loc_agnc_WeightedAverageContractualInterestRateOfInterestOnlyStrips_9C218BD5EFD88A003C67F0C8A49D2A06" xlink:type="locator" />
    <definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_WeightedAverageContractualInterestRateOfInterestOnlyStrips_9C218BD5EFD88A003C67F0C8A49D2A06" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio" xlink:label="loc_agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio_D3655F313BB2EB5A838DF0C8A49DD309" xlink:type="locator" />
    <definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_FuturePrepaymentRateAssumptionOfInvestmentPortfolio_D3655F313BB2EB5A838DF0C8A49DD309" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOfPrincipalOnlySecurities" xlink:label="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_A4342E3930AC254AEAACF0C8A49EB48B" xlink:type="locator" />
    <definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_agnc_WeightedAverageLifeOfPrincipalOnlySecurities_A4342E3930AC254AEAACF0C8A49EB48B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_46D0CD4F04D7BECB1949F0C8A49EE702" xlink:type="locator" />
    <definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_B1C10754A0DA4007DEB1F0C8A49C1049" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_46D0CD4F04D7BECB1949F0C8A49EE702" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesSummaryOfNetGainFromSaleOfAgencySecuritiesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_9943E0C3534F1B8FBA0B6227379B32B1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_9943E0C3534F1B8FBA0B6227379B32B1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_3F7C93C971CC28E4E4CB6227379B6EFB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_9943E0C3534F1B8FBA0B6227379B32B1" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_3F7C93C971CC28E4E4CB6227379B6EFB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_C0631DBAFF6C543BFA5A6227379BB408_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3F7C93C971CC28E4E4CB6227379B6EFB" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_C0631DBAFF6C543BFA5A6227379BB408_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_C0631DBAFF6C543BFA5A6227379BB408" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3F7C93C971CC28E4E4CB6227379B6EFB" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_C0631DBAFF6C543BFA5A6227379BB408" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_91B7F3BF0CE5C7D618EB6227379B2A00" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_C0631DBAFF6C543BFA5A6227379BB408" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_91B7F3BF0CE5C7D618EB6227379B2A00" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EligibleItemOrGroupForFairValueOptionAxis" xlink:label="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_B91D1248AD15920378EB6227379BC9BC" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_9943E0C3534F1B8FBA0B6227379B32B1" xlink:to="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_B91D1248AD15920378EB6227379BC9BC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueOptionEligibleItemOrGroupDomain" xlink:label="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_2FD51F21FDFE0F0765096227379B1A71_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_B91D1248AD15920378EB6227379BC9BC" xlink:to="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_2FD51F21FDFE0F0765096227379B1A71_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueOptionEligibleItemOrGroupDomain" xlink:label="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_2FD51F21FDFE0F0765096227379B1A71" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EligibleItemOrGroupForFairValueOptionAxis_B91D1248AD15920378EB6227379BC9BC" xlink:to="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_2FD51F21FDFE0F0765096227379B1A71" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableforsaleSecuritiesMember" xlink:label="loc_us-gaap_AvailableforsaleSecuritiesMember_69258AE79C95E3D41B476227379B8D52" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueOptionEligibleItemOrGroupDomain_2FD51F21FDFE0F0765096227379B1A71" xlink:to="loc_us-gaap_AvailableforsaleSecuritiesMember_69258AE79C95E3D41B476227379B8D52" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnderlyingAssetClassAxis" xlink:label="loc_us-gaap_UnderlyingAssetClassAxis_A1297EFBD2CA3FA469036227379B2E0B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_9943E0C3534F1B8FBA0B6227379B32B1" xlink:to="loc_us-gaap_UnderlyingAssetClassAxis_A1297EFBD2CA3FA469036227379B2E0B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnderlyingAssetClassDomain" xlink:label="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_UnderlyingAssetClassAxis_A1297EFBD2CA3FA469036227379B2E0B" xlink:to="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnderlyingAssetClassDomain" xlink:label="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_UnderlyingAssetClassAxis_A1297EFBD2CA3FA469036227379B2E0B" xlink:to="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestOnlyAndPrincipalOnlyStripMember" xlink:label="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_119FE190B6802E31028A6227379BAF8C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585" xlink:to="loc_agnc_InterestOnlyAndPrincipalOnlyStripMember_119FE190B6802E31028A6227379BAF8C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_E8EA4619502DE8144A756227379BEBFD" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_UnderlyingAssetClassDomain_F6D738F5ED74038E12B36227379BA585" xlink:to="loc_us-gaap_AgencySecuritiesMember_E8EA4619502DE8144A756227379BEBFD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainLossOnSecurities" xlink:label="loc_us-gaap_UnrealizedGainLossOnSecurities_EB4EA305A9AC05F4C8A96227379B506B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_UnrealizedGainLossOnSecurities_EB4EA305A9AC05F4C8A96227379B506B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_CostOfSaleOfAvailableForSaleSecuities" xlink:label="loc_agnc_CostOfSaleOfAvailableForSaleSecuities_D4D8A7C7B8115E825A4C6227379B0D4C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_agnc_CostOfSaleOfAvailableForSaleSecuities_D4D8A7C7B8115E825A4C6227379B0D4C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_DCCE65945071AC1866D16227379B7F0F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_DCCE65945071AC1866D16227379B7F0F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS" xlink:label="loc_us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS_E118A0B1E248B37F52E56227379B7CBB" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS_E118A0B1E248B37F52E56227379B7CBB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesRealizedGainLoss" xlink:label="loc_us-gaap_MarketableSecuritiesRealizedGainLoss_00522AB9BC082B3619556227379BC0A2" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_MarketableSecuritiesRealizedGainLoss_00522AB9BC082B3619556227379BC0A2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_3EDD7A26C7C54E45A96A6227379BA959" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_E80E7C0DF0D6601616266227379BBE5E" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_3EDD7A26C7C54E45A96A6227379BA959" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/InvestmentSecuritiesTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_E064C3C7B47964E9C258F0C8A590D93A" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_0429000198A070D3EAEEF0C8A5904DE0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_E064C3C7B47964E9C258F0C8A590D93A" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_0429000198A070D3EAEEF0C8A5904DE0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_32CB877DCB113A407300F0C8A5904B36" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_0429000198A070D3EAEEF0C8A5904DE0" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_32CB877DCB113A407300F0C8A5904B36" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_29FA247D65468F6EA3C1F0C8A5908C0E_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_32CB877DCB113A407300F0C8A5904B36" xlink:to="loc_us-gaap_RelatedPartyDomain_29FA247D65468F6EA3C1F0C8A5908C0E_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_29FA247D65468F6EA3C1F0C8A5908C0E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_32CB877DCB113A407300F0C8A5904B36" xlink:to="loc_us-gaap_RelatedPartyDomain_29FA247D65468F6EA3C1F0C8A5908C0E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ManagementFeeExpense" xlink:label="loc_us-gaap_ManagementFeeExpense_CA632B0ACC8A227CCD6CF0C8A5902C02" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_E064C3C7B47964E9C258F0C8A590D93A" xlink:to="loc_us-gaap_ManagementFeeExpense_CA632B0ACC8A227CCD6CF0C8A5902C02" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_975F1C43AD8B9C74803FF0C8A590D9B6" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_E064C3C7B47964E9C258F0C8A590D93A" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_975F1C43AD8B9C74803FF0C8A590D9B6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableRelatedPartiesCurrent" xlink:label="loc_us-gaap_AccountsPayableRelatedPartiesCurrent_6E7CE8E9BD81D900CF2BF0C8A591CF9B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_E064C3C7B47964E9C258F0C8A590D93A" xlink:to="loc_us-gaap_AccountsPayableRelatedPartiesCurrent_6E7CE8E9BD81D900CF2BF0C8A591CF9B" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsNotes" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_8D0194461A31A5E80F15F0C8A56DE6A8" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D6A3764D38ECAB08363EF0C8A56D6A7C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_8D0194461A31A5E80F15F0C8A56DE6A8" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D6A3764D38ECAB08363EF0C8A56D6A7C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9DAC57A0D971C7508B2CF0C8A56D6AA4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D6A3764D38ECAB08363EF0C8A56D6A7C" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9DAC57A0D971C7508B2CF0C8A56D6AA4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_3FF500B0A421950CE1DCF0C8A56D8F1F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9DAC57A0D971C7508B2CF0C8A56D6AA4" xlink:to="loc_us-gaap_RelatedPartyDomain_3FF500B0A421950CE1DCF0C8A56D8F1F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_3FF500B0A421950CE1DCF0C8A56D8F1F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9DAC57A0D971C7508B2CF0C8A56D6AA4" xlink:to="loc_us-gaap_RelatedPartyDomain_3FF500B0A421950CE1DCF0C8A56D8F1F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_01A843846DF6FE21702AF0C8A56D821C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_8D0194461A31A5E80F15F0C8A56DE6A8" xlink:to="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_01A843846DF6FE21702AF0C8A56D821C" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/ManagementAgreementAndRelatedPartyTransactionsTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/Organization" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/OrganizationDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/PledgedAssetsDetails" xlink:type="extended">
    <loc xlink:href="agnc-20140630.xsd#agnc_OffsettingAssetsAndLiabilitiesLineItems" xlink:label="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:type="locator" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OffsettingAssetsAndLiabilitiesTable" xlink:label="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtSecurityAxis" xlink:label="loc_us-gaap_DebtSecurityAxis_DED7D9F48C0BE66AC0BD92D56DF339D0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_DebtSecurityAxis_DED7D9F48C0BE66AC0BD92D56DF339D0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_05F297C262E75037DB0992D56DF3995C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtSecurityAxis_DED7D9F48C0BE66AC0BD92D56DF339D0" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_05F297C262E75037DB0992D56DF3995C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_05F297C262E75037DB0992D56DF3995C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtSecurityAxis_DED7D9F48C0BE66AC0BD92D56DF339D0" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_05F297C262E75037DB0992D56DF3995C" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AssetsPledgedtoUsMember" xlink:label="loc_agnc_AssetsPledgedtoUsMember_AA5300B5A8C553A4D65E92D56DF3B2B1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_05F297C262E75037DB0992D56DF3995C" xlink:to="loc_agnc_AssetsPledgedtoUsMember_AA5300B5A8C553A4D65E92D56DF3B2B1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_3B2037D890AE486C971492D56DF30F01" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_3B2037D890AE486C971492D56DF30F01" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_3B2037D890AE486C971492D56DF30F01" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_3B2037D890AE486C971492D56DF30F01" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityUpTo30DaysMember" xlink:label="loc_us-gaap_MaturityUpTo30DaysMember_7636A246EBCE6CEE65C992D56DF3AB9D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:to="loc_us-gaap_MaturityUpTo30DaysMember_7636A246EBCE6CEE65C992D56DF3AB9D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_Maturity31To59DaysMember" xlink:label="loc_agnc_Maturity31To59DaysMember_DA6C8892634A1B3950FB92D56DF3900B" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:to="loc_agnc_Maturity31To59DaysMember_DA6C8892634A1B3950FB92D56DF3900B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_Maturity60To90DaysMember" xlink:label="loc_agnc_Maturity60To90DaysMember_089B76F4DC0D16EA9E4792D56DF3DF11" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:to="loc_agnc_Maturity60To90DaysMember_089B76F4DC0D16EA9E4792D56DF3DF11" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityOver90DaysMember" xlink:label="loc_us-gaap_MaturityOver90DaysMember_196CCD40CF0AE8E3C10392D56DF4B064" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:to="loc_us-gaap_MaturityOver90DaysMember_196CCD40CF0AE8E3C10392D56DF4B064" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityOvernightMember" xlink:label="loc_us-gaap_MaturityOvernightMember_E53712AA6D616ABAD86692D56DF4D320" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_39D9EEC04C15D0EDFC1892D56DF38AEF" xlink:to="loc_us-gaap_MaturityOvernightMember_E53712AA6D616ABAD86692D56DF4D320" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2E16F413F6A93355896692D56DF42A3B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2E16F413F6A93355896692D56DF42A3B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2E16F413F6A93355896692D56DF42A3B" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2E16F413F6A93355896692D56DF42A3B" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_3DC5FEF650B0FDCCD00792D56DF41147" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:to="loc_us-gaap_DerivativeMember_3DC5FEF650B0FDCCD00792D56DF41147" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ExcludingCashReceivedMember" xlink:label="loc_agnc_ExcludingCashReceivedMember_9A56AE20FB879342744692D56DF480B1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:to="loc_agnc_ExcludingCashReceivedMember_9A56AE20FB879342744692D56DF480B1" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnderPrimeBrokerAgreementsMember" xlink:label="loc_agnc_UnderPrimeBrokerAgreementsMember_1FD7FC5174D17248B86292D56DF432F6" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:to="loc_agnc_UnderPrimeBrokerAgreementsMember_1FD7FC5174D17248B86292D56DF432F6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_F34BFB16095B2783B66D92D56DF404E3" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_A4097EE2FC7CF4BA445192D56DF4D15A" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_F34BFB16095B2783B66D92D56DF404E3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassAxis" xlink:label="loc_invest_InvestmentSecuritiesClassAxis_F5DAB5C37AAC37859DA492D56DF4C4B8" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_invest_InvestmentSecuritiesClassAxis_F5DAB5C37AAC37859DA492D56DF4C4B8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_F5DAB5C37AAC37859DA492D56DF4C4B8" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_F5DAB5C37AAC37859DA492D56DF4C4B8" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_77B529731330A0A2794092D56DF4DD62" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_us-gaap_DerivativeMember_77B529731330A0A2794092D56DF4DD62" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReverseRepurchaseAgreementsMember" xlink:label="loc_agnc_ReverseRepurchaseAgreementsMember_83A25285710964F9993F92D56DF4FFB2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_agnc_ReverseRepurchaseAgreementsMember_83A25285710964F9993F92D56DF4FFB2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_999CBCEA005AE20AFC7392D56DF46A4D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_999CBCEA005AE20AFC7392D56DF46A4D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnderPrimeBrokerAgreementsMember" xlink:label="loc_agnc_UnderPrimeBrokerAgreementsMember_03864D0069259F86C72292D56DF42961" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_agnc_UnderPrimeBrokerAgreementsMember_03864D0069259F86C72292D56DF42961" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_IncludesSoldButNotYetSettledSecuritiesMember" xlink:label="loc_agnc_IncludesSoldButNotYetSettledSecuritiesMember_1A5621E6CD28126F275792D56DF4782F" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_agnc_IncludesSoldButNotYetSettledSecuritiesMember_1A5621E6CD28126F275792D56DF4782F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_4F1E4884A68BE28368A792D56DF440A8" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_4F1E4884A68BE28368A792D56DF440A8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_CDD163F087BAFAD1B1AA92D56DF4BB08" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_0C22713D321343667F9092D56DF4B801" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_CDD163F087BAFAD1B1AA92D56DF4BB08" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_D1D20B81FB8BB2E00FDE92D56DF4DF07" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_InvestmentTypeAxis_D1D20B81FB8BB2E00FDE92D56DF4DF07" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_D1D20B81FB8BB2E00FDE92D56DF4DF07" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_D1D20B81FB8BB2E00FDE92D56DF4DF07" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_06E8F679505F8A74542B92D56DFA42A3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_06E8F679505F8A74542B92D56DFA42A3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_5FDAD3D3ADE72DF27E4692D56DFAABF2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:to="loc_us-gaap_AgencySecuritiesMember_5FDAD3D3ADE72DF27E4692D56DFAABF2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_A463623902174C749AE792D56DFA9392" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:to="loc_us-gaap_DerivativeMember_A463623902174C749AE792D56DFA9392" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_52FD3F4FDB2B71352AE292D56DFAC608" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_8D522CD1CC82C5B84EFE92D56DF428F1" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_52FD3F4FDB2B71352AE292D56DFAC608" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_FCB29160FD5BC79403FE92D56DFA40CF" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_FCB29160FD5BC79403FE92D56DFA40CF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_FCB29160FD5BC79403FE92D56DFA40CF" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_FCB29160FD5BC79403FE92D56DFA40CF" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_A1CF7A28B4907BF8556C92D56DFAF8A7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_A1CF7A28B4907BF8556C92D56DFAF8A7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReverseRepurchaseAgreementsMember" xlink:label="loc_agnc_ReverseRepurchaseAgreementsMember_A1E31D2D4CF53B807A7392D56DFA5D4D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_9B042028E30EDB258D0092D56DFA9A26" xlink:to="loc_agnc_ReverseRepurchaseAgreementsMember_A1E31D2D4CF53B807A7392D56DFA5D4D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_756D19100806995835E692D56DFA8C35" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_756D19100806995835E692D56DFA8C35" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_756D19100806995835E692D56DFA8C35" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_756D19100806995835E692D56DFA8C35" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilityMember" xlink:label="loc_us-gaap_LiabilityMember_432E1901B5C2C0F73D7492D56DFABB15" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C" xlink:to="loc_us-gaap_LiabilityMember_432E1901B5C2C0F73D7492D56DFABB15" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsMember" xlink:label="loc_us-gaap_AssetsMember_5D3DA333722E55ACF45D92D56DFA2BA4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_52DC4CE4F34D94505A4492D56DFA255C" xlink:to="loc_us-gaap_AssetsMember_5D3DA333722E55ACF45D92D56DFA2BA4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_169F3560C84FED89E3AD92D56DFAB620" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_169F3560C84FED89E3AD92D56DFAB620" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_03A4747437FE5CF5F85D92D56DFA5966_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_169F3560C84FED89E3AD92D56DFAB620" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_03A4747437FE5CF5F85D92D56DFA5966_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_03A4747437FE5CF5F85D92D56DFA5966" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_169F3560C84FED89E3AD92D56DFAB620" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_03A4747437FE5CF5F85D92D56DFA5966" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SwaptionMember" xlink:label="loc_us-gaap_SwaptionMember_441F21B75AB27490A93592D56DFAA9BC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_03A4747437FE5CF5F85D92D56DFA5966" xlink:to="loc_us-gaap_SwaptionMember_441F21B75AB27490A93592D56DFAA9BC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_8B53FE99EFBF112BF5C292D56DFAC5C3" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesTable_3AEAEA54B2C70CDBC51E92D56DF3FDDA" xlink:to="loc_us-gaap_DerivativeByNatureAxis_8B53FE99EFBF112BF5C292D56DFAC5C3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_8414BB1F4FBC6842EBF292D56DFAC544_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_8B53FE99EFBF112BF5C292D56DFAC5C3" xlink:to="loc_agnc_DerivativebyNatureDomain_8414BB1F4FBC6842EBF292D56DFAC544_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_8414BB1F4FBC6842EBF292D56DFAC544" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_8B53FE99EFBF112BF5C292D56DFAC5C3" xlink:to="loc_agnc_DerivativebyNatureDomain_8414BB1F4FBC6842EBF292D56DFAC544" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_24D023BF01B2A501CF2F92D56DFAEA4F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_8414BB1F4FBC6842EBF292D56DFAC544" xlink:to="loc_us-gaap_InterestRateSwapMember_24D023BF01B2A501CF2F92D56DFAEA4F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_RiskOfRepurchaseAgreementToStockholdersEquity" xlink:label="loc_agnc_RiskOfRepurchaseAgreementToStockholdersEquity_304CC3775BD9EE4F91C092D56DFB33F3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_RiskOfRepurchaseAgreementToStockholdersEquity_304CC3775BD9EE4F91C092D56DFB33F3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue" xlink:label="loc_us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue_0100D60D26F1D3072CBB92D56DFB3212" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue_0100D60D26F1D3072CBB92D56DFB3212" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_B93E58442CAF673A842D92D56DFBA5CE" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_B93E58442CAF673A842D92D56DFBA5CE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_7E619B761F1B2A5A0D6592D56DFBDCD2" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_7E619B761F1B2A5A0D6592D56DFBDCD2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GrossAmountOfRecognizedAssetsLiabilities" xlink:label="loc_agnc_GrossAmountOfRecognizedAssetsLiabilities_A3AB4582685E69FBCDEE92D56DFB1602" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_GrossAmountOfRecognizedAssetsLiabilities_A3AB4582685E69FBCDEE92D56DFB1602" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet" xlink:label="loc_agnc_NetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet_7F526135464019080FC792D56DFB1621" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_NetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet_7F526135464019080FC792D56DFB1621" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GrossAmountsOfFinancialInstrumentsNotOffsetOnBalanceSheet" xlink:label="loc_agnc_GrossAmountsOfFinancialInstrumentsNotOffsetOnBalanceSheet_E94C00BD918758087AA892D56DFB61CB" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_GrossAmountsOfFinancialInstrumentsNotOffsetOnBalanceSheet_E94C00BD918758087AA892D56DFB61CB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_GrossAmountsOfCashCollateralNotOffsetOnBalanceSheet" xlink:label="loc_agnc_GrossAmountsOfCashCollateralNotOffsetOnBalanceSheet_31B82CA39D8EF133E20792D56DFBFE38" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_GrossAmountsOfCashCollateralNotOffsetOnBalanceSheet_31B82CA39D8EF133E20792D56DFBFE38" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral_B47E17CE181DDCB0015E92D56DFBFEF2" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral_B47E17CE181DDCB0015E92D56DFBFEF2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral_843A4FAC4DDFFBDCD7B192D56DFB8817" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral_843A4FAC4DDFFBDCD7B192D56DFB8817" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetAmountAfterDeductingGrossAmountsNotOffsetOnBalanceSheetFromNetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet" xlink:label="loc_agnc_NetAmountAfterDeductingGrossAmountsNotOffsetOnBalanceSheetFromNetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet_BF6D35C94C9A24344DD592D56DFB8FD6" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_NetAmountAfterDeductingGrossAmountsNotOffsetOnBalanceSheetFromNetAmountOfAssetsLiabilitiesPresentedOnBalanceSheet_BF6D35C94C9A24344DD592D56DFB8FD6" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest" xlink:label="loc_agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest_2A94804814030D1FC29D92D56DFB7A29" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest_2A94804814030D1FC29D92D56DFB7A29" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_7FA180252C0DF67FB33292D56DFB255E" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_7FA180252C0DF67FB33292D56DFB255E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest" xlink:label="loc_agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest_122199DF8529800D0B5092D56DFBD5CC" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest_122199DF8529800D0B5092D56DFBD5CC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost" xlink:label="loc_agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost_B58644E504F3AEF1E9D792D56DFBAB17" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost_B58644E504F3AEF1E9D792D56DFBAB17" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest" xlink:label="loc_agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest_52DB67FB8A8EAF20962692D56DFBB3EB" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest_52DB67FB8A8EAF20962692D56DFBB3EB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_RestrictedCashandSecuritiesPledged" xlink:label="loc_agnc_RestrictedCashandSecuritiesPledged_E224FF38E465D7DA4BEC92D56DFB37CD" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_agnc_RestrictedCashandSecuritiesPledged_E224FF38E465D7DA4BEC92D56DFB37CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditDerivativeMaximumExposureUndiscounted" xlink:label="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_58C96B6A2CBC1BEC47EB92D56DFBE29B" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_OffsettingAssetsAndLiabilitiesLineItems_F79F3D7CE1C32E5D3C8D92D56DFA6F74" xlink:to="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_58C96B6A2CBC1BEC47EB92D56DFBE29B" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/PledgedAssetsNotes" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/PledgedAssetsPledgedAssetsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtSecurityAxis" xlink:label="loc_us-gaap_DebtSecurityAxis_A45B4360D511BF018E7FF0C8A47A7773" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:to="loc_us-gaap_DebtSecurityAxis_A45B4360D511BF018E7FF0C8A47A7773" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_328BC920ABA5855BCA53F0C8A47A220A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtSecurityAxis_A45B4360D511BF018E7FF0C8A47A7773" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_328BC920ABA5855BCA53F0C8A47A220A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtSecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_328BC920ABA5855BCA53F0C8A47A220A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtSecurityAxis_A45B4360D511BF018E7FF0C8A47A7773" xlink:to="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_328BC920ABA5855BCA53F0C8A47A220A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AssetsPledgedtoUsMember" xlink:label="loc_agnc_AssetsPledgedtoUsMember_E1D979E8D5768E82FD92F0C8A47A8CCF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtSecuritiesDomain_328BC920ABA5855BCA53F0C8A47A220A" xlink:to="loc_agnc_AssetsPledgedtoUsMember_E1D979E8D5768E82FD92F0C8A47A8CCF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_F2F915E4F604FA5BBF7AF0C8A47B6893" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_F2F915E4F604FA5BBF7AF0C8A47B6893" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_F2F915E4F604FA5BBF7AF0C8A47B6893" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_F2F915E4F604FA5BBF7AF0C8A47B6893" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityUpTo30DaysMember" xlink:label="loc_us-gaap_MaturityUpTo30DaysMember_1AD5268AA57D6FAF962BF0C8A47B8BFF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:to="loc_us-gaap_MaturityUpTo30DaysMember_1AD5268AA57D6FAF962BF0C8A47B8BFF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_Maturity31To59DaysMember" xlink:label="loc_agnc_Maturity31To59DaysMember_60FFF1E8FE1FD8E9F129F0C8A47B4203" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:to="loc_agnc_Maturity31To59DaysMember_60FFF1E8FE1FD8E9F129F0C8A47B4203" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_Maturity60To90DaysMember" xlink:label="loc_agnc_Maturity60To90DaysMember_670EDE54E170B41DD9DFF0C8A47B74CC" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:to="loc_agnc_Maturity60To90DaysMember_670EDE54E170B41DD9DFF0C8A47B74CC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityOver90DaysMember" xlink:label="loc_us-gaap_MaturityOver90DaysMember_C34C39BA53E167E2DEC9F0C8A47B4046" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:to="loc_us-gaap_MaturityOver90DaysMember_C34C39BA53E167E2DEC9F0C8A47B4046" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityOvernightMember" xlink:label="loc_us-gaap_MaturityOvernightMember_6B1F5B838AD286817BD8F0C8A47B6770" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_7E3FBF177D798EA9DE1DF0C8A47B1F11" xlink:to="loc_us-gaap_MaturityOvernightMember_6B1F5B838AD286817BD8F0C8A47B6770" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_38B8A5B90640F2A7F2CEF0C8A47B2840" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_38B8A5B90640F2A7F2CEF0C8A47B2840" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_38B8A5B90640F2A7F2CEF0C8A47B2840" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_38B8A5B90640F2A7F2CEF0C8A47B2840" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_5DEDA9F958C75E966A62F0C8A47BCBAC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:to="loc_us-gaap_DerivativeMember_5DEDA9F958C75E966A62F0C8A47BCBAC" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ExcludingCashReceivedMember" xlink:label="loc_agnc_ExcludingCashReceivedMember_03F7CF6F857AD872B835F0C8A47B530A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:to="loc_agnc_ExcludingCashReceivedMember_03F7CF6F857AD872B835F0C8A47B530A" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnderPrimeBrokerAgreementsMember" xlink:label="loc_agnc_UnderPrimeBrokerAgreementsMember_AC686A922FCE169B1183F0C8A47B2484" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:to="loc_agnc_UnderPrimeBrokerAgreementsMember_AC686A922FCE169B1183F0C8A47B2484" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_7B96AFBC9F67FE225515F0C8A47BEA7E" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_7145A88B48B10A7D5E6EF0C8A47B4729" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_7B96AFBC9F67FE225515F0C8A47BEA7E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassAxis" xlink:label="loc_invest_InvestmentSecuritiesClassAxis_CEBD40BF7446B4F00D60F0C8A47B6A4A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:to="loc_invest_InvestmentSecuritiesClassAxis_CEBD40BF7446B4F00D60F0C8A47B6A4A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_CEBD40BF7446B4F00D60F0C8A47B6A4A" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_CEBD40BF7446B4F00D60F0C8A47B6A4A" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_43BC1276B7764E2F05F2F0C8A47B7619" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_us-gaap_DerivativeMember_43BC1276B7764E2F05F2F0C8A47B7619" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_9203CBF6C086F1EC23BCF0C8A47C8519" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_9203CBF6C086F1EC23BCF0C8A47C8519" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_14DCDC8D950FEC51A2D4F0C8A47C93C3" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_14DCDC8D950FEC51A2D4F0C8A47C93C3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_7A63F4CC67AD36E63865F0C8A47CFA69" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_7A63F4CC67AD36E63865F0C8A47CFA69" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_UnderPrimeBrokerAgreementsMember" xlink:label="loc_agnc_UnderPrimeBrokerAgreementsMember_6FB32B3ADB0EA6BA0B31F0C8A47C39DB" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_agnc_UnderPrimeBrokerAgreementsMember_6FB32B3ADB0EA6BA0B31F0C8A47C39DB" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_IncludesSoldButNotYetSettledSecuritiesMember" xlink:label="loc_agnc_IncludesSoldButNotYetSettledSecuritiesMember_09A324FB25DBA558089AF0C8A47C0EE9" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_agnc_IncludesSoldButNotYetSettledSecuritiesMember_09A324FB25DBA558089AF0C8A47C0EE9" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReverseRepurchaseAgreementsMember" xlink:label="loc_agnc_ReverseRepurchaseAgreementsMember_563F37433F58C426BB4AF0C8A47CD163" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_00DEF9C5D54D17116F55F0C8A47B9B0A" xlink:to="loc_agnc_ReverseRepurchaseAgreementsMember_563F37433F58C426BB4AF0C8A47CD163" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_2FA41143F28D6C465282F0C8A47CBF45" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_7079E91A84208B86EB4CF0C8A47AB617" xlink:to="loc_us-gaap_InvestmentTypeAxis_2FA41143F28D6C465282F0C8A47CBF45" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_2FA41143F28D6C465282F0C8A47CBF45" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_2FA41143F28D6C465282F0C8A47CBF45" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_DC35F0B5BA03B98D17F7F0C8A47CA48B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070" xlink:to="loc_us-gaap_AgencySecuritiesMember_DC35F0B5BA03B98D17F7F0C8A47CA48B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_B62AC203DAC0F10F8EA8F0C8A47C5EE7" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_B62AC203DAC0F10F8EA8F0C8A47C5EE7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeMember" xlink:label="loc_us-gaap_DerivativeMember_40CF1B1DE644C678B0F7F0C8A47CF573" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_25A9A99EEA34E1C94962F0C8A47CC070" xlink:to="loc_us-gaap_DerivativeMember_40CF1B1DE644C678B0F7F0C8A47CF573" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue" xlink:label="loc_us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue_708484666990ADC620E8F0C8A47CB4B6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue_708484666990ADC620E8F0C8A47CB4B6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_B3CF15DFBEBEEFB02534F0C8A47CCA82" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral_B3CF15DFBEBEEFB02534F0C8A47CCA82" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue" xlink:label="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_9BFC97604E24B1E512F7F0C8A47C566B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_ObligationToReturnSecuritiesBorrowedUnderReverseRepurchaseAgreementsAtFairValue_9BFC97604E24B1E512F7F0C8A47C566B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest" xlink:label="loc_agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest_858D72AB6260E82901BDF0C8A47C82BD" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_AvailableForSaleSecuritiesPledgedAsCollateralAccruedInterest_858D72AB6260E82901BDF0C8A47C82BD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_47BBAABF8CCE40C870C7F0C8A47DBADD" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_47BBAABF8CCE40C870C7F0C8A47DBADD" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest" xlink:label="loc_agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest_0E8D81D98A54786DC2F5F0C8A47D6AB4" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_TotalFairValueOfAgencySecuritiesPledgedAndAccruedInterest_0E8D81D98A54786DC2F5F0C8A47D6AB4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost" xlink:label="loc_agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost_6A92BE486607B5CE74F5F0C8A47D9179" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_AgencySecuritiesPledgedAsCollateralAmortizedCost_6A92BE486607B5CE74F5F0C8A47D9179" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest" xlink:label="loc_agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest_5073C09A2ACF6D13CAEBF0C8A47DE002" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_AgencySecuritiesPledgedAsCollateralAccruedInterest_5073C09A2ACF6D13CAEBF0C8A47DE002" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_RestrictedCashandSecuritiesPledged" xlink:label="loc_agnc_RestrictedCashandSecuritiesPledged_1521E7CBC73F82A89437F0C8A47D8D76" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_275B901294384EE166B3F0C8A47CF2DD" xlink:to="loc_agnc_RestrictedCashandSecuritiesPledged_1521E7CBC73F82A89437F0C8A47D8D76" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/PledgedAssetsTables" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OffsettingLiabilitiesLineItems" xlink:label="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OffsettingLiabilitiesTable" xlink:label="loc_us-gaap_OffsettingLiabilitiesTable_C7BE58B0A19B9C983C0BAD0F0CBEA773" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_us-gaap_OffsettingLiabilitiesTable_C7BE58B0A19B9C983C0BAD0F0CBEA773" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OffsettingOfFinancialAssetsAndLiabilitiesAxis" xlink:label="loc_agnc_OffsettingOfFinancialAssetsAndLiabilitiesAxis_D83A2FD46F1BDFB05AFDAD0F0CBE9E84" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OffsettingLiabilitiesTable_C7BE58B0A19B9C983C0BAD0F0CBEA773" xlink:to="loc_agnc_OffsettingOfFinancialAssetsAndLiabilitiesAxis_D83A2FD46F1BDFB05AFDAD0F0CBE9E84" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_179A7672FE5109F987F9AD0F0CBE7222_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_agnc_OffsettingOfFinancialAssetsAndLiabilitiesAxis_D83A2FD46F1BDFB05AFDAD0F0CBE9E84" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_179A7672FE5109F987F9AD0F0CBE7222_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_179A7672FE5109F987F9AD0F0CBE7222" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_agnc_OffsettingOfFinancialAssetsAndLiabilitiesAxis_D83A2FD46F1BDFB05AFDAD0F0CBE9E84" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_179A7672FE5109F987F9AD0F0CBE7222" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock" xlink:label="loc_us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock_3528E40AFD3D8FF3A2C9AD0F0CBE35C3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock_3528E40AFD3D8FF3A2C9AD0F0CBE35C3" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SchedulesOfSecuritiesPledgedAsCollateralUnderRepurchaseAgreementTextBlockTableTextBlock" xlink:label="loc_agnc_SchedulesOfSecuritiesPledgedAsCollateralUnderRepurchaseAgreementTextBlockTableTextBlock_D9D0703B3D35D54590DDAD0F0CBFAD44" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_agnc_SchedulesOfSecuritiesPledgedAsCollateralUnderRepurchaseAgreementTextBlockTableTextBlock_D9D0703B3D35D54590DDAD0F0CBFAD44" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ScheduleofSecuritiesandCashPledgedasCollateralfromCounterpartiesTableTextBlock" xlink:label="loc_agnc_ScheduleofSecuritiesandCashPledgedasCollateralfromCounterpartiesTableTextBlock_7DF2730DEBADD48E741EAD0F0CBF9A71" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_agnc_ScheduleofSecuritiesandCashPledgedasCollateralfromCounterpartiesTableTextBlock_7DF2730DEBADD48E741EAD0F0CBF9A71" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OffsettingAssetsTableTextBlock" xlink:label="loc_us-gaap_OffsettingAssetsTableTextBlock_28A2C14D5EA978152729AD0F0CBFB9D8" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_us-gaap_OffsettingAssetsTableTextBlock_28A2C14D5EA978152729AD0F0CBFB9D8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OffsettingLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_OffsettingLiabilitiesTableTextBlock_7B71A3CF11F0C1A49D8AAD0F0CBFD58B" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OffsettingLiabilitiesLineItems_6DE519E85FA493EACC41AD0F0CBEB4DC" xlink:to="loc_us-gaap_OffsettingLiabilitiesTableTextBlock_7B71A3CF11F0C1A49D8AAD0F0CBFD58B" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebt" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtNarrativeDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_2EEB10DB8A305E42566F92D56EF5D748" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_648BB63F7BC6A026CB1492D56EF5E168" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2EEB10DB8A305E42566F92D56EF5D748" xlink:to="loc_us-gaap_DebtInstrumentTable_648BB63F7BC6A026CB1492D56EF5E168" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_E12037BC2E4383D4C41A92D56EF5AEA7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_648BB63F7BC6A026CB1492D56EF5E168" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_E12037BC2E4383D4C41A92D56EF5AEA7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FC8C9A8E18541BA79A6B92D56EF5DAE7_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_E12037BC2E4383D4C41A92D56EF5AEA7" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FC8C9A8E18541BA79A6B92D56EF5DAE7_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FC8C9A8E18541BA79A6B92D56EF5DAE7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_E12037BC2E4383D4C41A92D56EF5AEA7" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FC8C9A8E18541BA79A6B92D56EF5DAE7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_C2E703F9CF3038A2646B92D56EF5F04F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_648BB63F7BC6A026CB1492D56EF5E168" xlink:to="loc_us-gaap_DebtInstrumentAxis_C2E703F9CF3038A2646B92D56EF5F04F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ED90F63C5A6D14BD293492D56EF56B09_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_C2E703F9CF3038A2646B92D56EF5F04F" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ED90F63C5A6D14BD293492D56EF56B09_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ED90F63C5A6D14BD293492D56EF56B09" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_C2E703F9CF3038A2646B92D56EF5F04F" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ED90F63C5A6D14BD293492D56EF56B09" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_WeightedAverageLifeOtherDebt" xlink:label="loc_agnc_WeightedAverageLifeOtherDebt_E2A54051BA3C0B40EFFA92D56EF5A10F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2EEB10DB8A305E42566F92D56EF5D748" xlink:to="loc_agnc_WeightedAverageLifeOtherDebt_E2A54051BA3C0B40EFFA92D56EF5A10F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecuredDebtDollarRolls" xlink:label="loc_us-gaap_SecuredDebtDollarRolls_E7F0015E591987E4714492D56EF5B762" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2EEB10DB8A305E42566F92D56EF5D748" xlink:to="loc_us-gaap_SecuredDebtDollarRolls_E7F0015E591987E4714492D56EF5B762" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtRepurchaseAgreementsPolicies" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtRepurchaseArrangementsAndWeightedAverageInterestRatesClassifiedByOriginalMaturitiesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable" xlink:label="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentAxis" xlink:label="loc_invest_InvestmentAxis_54021543D796E16B760492CAD562245C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:to="loc_invest_InvestmentAxis_54021543D796E16B760492CAD562245C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_65051DE6E28358F4716692CAD56289BD_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentAxis_54021543D796E16B760492CAD562245C" xlink:to="loc_invest_InvestmentDomain_65051DE6E28358F4716692CAD56289BD_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_65051DE6E28358F4716692CAD56289BD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentAxis_54021543D796E16B760492CAD562245C" xlink:to="loc_invest_InvestmentDomain_65051DE6E28358F4716692CAD56289BD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_008C651FA539A1D7223D92CAD5621CEF" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentDomain_65051DE6E28358F4716692CAD56289BD" xlink:to="loc_us-gaap_AgencySecuritiesMember_008C651FA539A1D7223D92CAD5621CEF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_341BF0136FEB851B513492CAD56353B2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:to="loc_us-gaap_DebtInstrumentAxis_341BF0136FEB851B513492CAD56353B2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4B7389F62A5400D2DCA092CAD563396D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_341BF0136FEB851B513492CAD56353B2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4B7389F62A5400D2DCA092CAD563396D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4B7389F62A5400D2DCA092CAD563396D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_341BF0136FEB851B513492CAD56353B2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4B7389F62A5400D2DCA092CAD563396D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAgreementsMember" xlink:label="loc_us-gaap_RepurchaseAgreementsMember_484BCE7883ADBD72550392CAD5639450" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4B7389F62A5400D2DCA092CAD563396D" xlink:to="loc_us-gaap_RepurchaseAgreementsMember_484BCE7883ADBD72550392CAD5639450" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_2220D97B7B738A7A7B1C92CAD563A545" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_2220D97B7B738A7A7B1C92CAD563A545" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_A05DA73097B8FFE7C2D392CAD563B381_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_2220D97B7B738A7A7B1C92CAD563A545" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_A05DA73097B8FFE7C2D392CAD563B381_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_A05DA73097B8FFE7C2D392CAD563B381" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_2220D97B7B738A7A7B1C92CAD563A545" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_A05DA73097B8FFE7C2D392CAD563B381" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MortgageBackedSecuritiesMember" xlink:label="loc_us-gaap_MortgageBackedSecuritiesMember_AE93EFDEF1771E700E2792CAD56372B7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_A05DA73097B8FFE7C2D392CAD563B381" xlink:to="loc_us-gaap_MortgageBackedSecuritiesMember_AE93EFDEF1771E700E2792CAD56372B7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_8346E29BE47951FD642992CAD56317F9" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:to="loc_dei_LegalEntityAxis_8346E29BE47951FD642992CAD56317F9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_955585E4D22DFD5CA44E92CAD563B9B5_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_8346E29BE47951FD642992CAD56317F9" xlink:to="loc_dei_EntityDomain_955585E4D22DFD5CA44E92CAD563B9B5_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_955585E4D22DFD5CA44E92CAD563B9B5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_8346E29BE47951FD642992CAD56317F9" xlink:to="loc_dei_EntityDomain_955585E4D22DFD5CA44E92CAD563B9B5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_B3ED3F2200E66312518692CAD56394F4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_955585E4D22DFD5CA44E92CAD563B9B5" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_B3ED3F2200E66312518692CAD56394F4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_4A3098E7E6F57824A05C92CAD563516E" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAssetsSoldUnderAgreementsToRepurchaseTable_14DC0C55FFD52B9EA57792CAD562F0B6" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_4A3098E7E6F57824A05C92CAD563516E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_4A3098E7E6F57824A05C92CAD563516E" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_4A3098E7E6F57824A05C92CAD563516E" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaturityUpTo30DaysMember" xlink:label="loc_us-gaap_MaturityUpTo30DaysMember_1F2BAAE778491654BD6092CAD563E979" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_us-gaap_MaturityUpTo30DaysMember_1F2BAAE778491654BD6092CAD563E979" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ThirtyOneToNinetyMember" xlink:label="loc_agnc_ThirtyOneToNinetyMember_27FB7FDA182BB587D40D92CAD56305B4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_ThirtyOneToNinetyMember_27FB7FDA182BB587D40D92CAD56305B4" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A4to6MonthsMember" xlink:label="loc_agnc_A4to6MonthsMember_6FAD565A537718C0988892CFE60125B6" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A4to6MonthsMember_6FAD565A537718C0988892CFE60125B6" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A7to9monthsMember" xlink:label="loc_agnc_A7to9monthsMember_547860623095A34159D292D19347E4E5" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A7to9monthsMember_547860623095A34159D292D19347E4E5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A10to12MonthsMember" xlink:label="loc_agnc_A10to12MonthsMember_845A2CDE59E97E6AAF9C92D23B4BFB5D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A10to12MonthsMember_845A2CDE59E97E6AAF9C92D23B4BFB5D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A13to24MonthsMember" xlink:label="loc_agnc_A13to24MonthsMember_1DE4BBF81D0CB705156692D2F7BBF2D6" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A13to24MonthsMember_1DE4BBF81D0CB705156692D2F7BBF2D6" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A25to36monthsMember" xlink:label="loc_agnc_A25to36monthsMember_8CE099F5A32AA9F72D2292D37939E8BF" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A25to36monthsMember_8CE099F5A32AA9F72D2292D37939E8BF" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A37to48monthsMember" xlink:label="loc_agnc_A37to48monthsMember_1367E61E504F877DBB6392D456EA2452" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A37to48monthsMember_1367E61E504F877DBB6392D456EA2452" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_A49to60MonthsMember" xlink:label="loc_agnc_A49to60MonthsMember_793792FE3619BF4B7C4E92D4D74EF1D5" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_C9C6286E4AA6DA2B148B92CAD5639FC8" xlink:to="loc_agnc_A49to60MonthsMember_793792FE3619BF4B7C4E92D4D74EF1D5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLongTermDebt" xlink:label="loc_us-gaap_OtherLongTermDebt_C1066D6B2FE261E4FE1B92CAD5635229" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_us-gaap_OtherLongTermDebt_C1066D6B2FE261E4FE1B92CAD5635229" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SpreadOverLibor" xlink:label="loc_agnc_SpreadOverLibor_4E8293C49E649D8A75B592CAD563C0B2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_agnc_SpreadOverLibor_4E8293C49E649D8A75B592CAD563C0B2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_2FD027DB7E97260C226092CAD56365C6" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_2FD027DB7E97260C226092CAD56365C6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_D437D00B9CC4A689265D92CAD564DA61" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_D437D00B9CC4A689265D92CAD564DA61" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortTermDebtWeightedAverageInterestRate" xlink:label="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_D628AEA7540CBC52B49492CAD5640EB8" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_D628AEA7540CBC52B49492CAD5640EB8" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_RepurchaseAgreementsWeightedAverageDaysToMaturity" xlink:label="loc_agnc_RepurchaseAgreementsWeightedAverageDaysToMaturity_4407415F58E12315148B92CAD564B2AF" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2EA0046069A82FA5DAF992CAD563BDDB" xlink:to="loc_agnc_RepurchaseAgreementsWeightedAverageDaysToMaturity_4407415F58E12315148B92CAD564B2AF" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/RepurchaseAgreementsAndOtherDebtTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/StockholdersEquity" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/StockholdersEquityDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:type="locator" />
    <loc xlink:href="agnc-20140630.xsd#agnc_StockholdersEquityTable" xlink:label="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_FFA40EA26FDE263CD7ADB0A3E2450521" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_FFA40EA26FDE263CD7ADB0A3E2450521" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_FFA40EA26FDE263CD7ADB0A3E2450521" xlink:to="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_FFA40EA26FDE263CD7ADB0A3E2450521" xlink:to="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredClassBMember" xlink:label="loc_us-gaap_PreferredClassBMember_E6714721252EF84CFB41B0A3E24563BD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6" xlink:to="loc_us-gaap_PreferredClassBMember_E6714721252EF84CFB41B0A3E24563BD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_DCBEB551892250862489B0A3E24564CF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_A07C13D86AC29326520FB0A3E24530F6" xlink:to="loc_us-gaap_CommonStockMember_DCBEB551892250862489B0A3E24564CF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_CF6F2C14B6F5CFA9B1CBB0A3E2452F90" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_StatementClassOfStockAxis_CF6F2C14B6F5CFA9B1CBB0A3E2452F90" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_CF6F2C14B6F5CFA9B1CBB0A3E2452F90" xlink:to="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_CF6F2C14B6F5CFA9B1CBB0A3E2452F90" xlink:to="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredClassBMember" xlink:label="loc_us-gaap_PreferredClassBMember_0FF6BBDF2270C067FB63B0A3E24594C9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:to="loc_us-gaap_PreferredClassBMember_0FF6BBDF2270C067FB63B0A3E24594C9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_FCAD6C46C1D005E76F4FB0A3E2456F84" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_FCAD6C46C1D005E76F4FB0A3E2456F84" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredClassAMember" xlink:label="loc_us-gaap_PreferredClassAMember_AA245765DFF71085F8AEB0A3E2459CC4" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:to="loc_us-gaap_PreferredClassAMember_AA245765DFF71085F8AEB0A3E2459CC4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_90ECF35D4E102A373DC6B0A3E2459C8A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_65C61CDAEECB9BD6A47CB0A3E245DA91" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_90ECF35D4E102A373DC6B0A3E2459C8A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentAxis" xlink:label="loc_invest_InvestmentAxis_85E60D17B17B2FBA4B1DB0A3E24558FB" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_invest_InvestmentAxis_85E60D17B17B2FBA4B1DB0A3E24558FB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_A9E8F3FC6BA184E3D846B0A3E245BF0F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentAxis_85E60D17B17B2FBA4B1DB0A3E24558FB" xlink:to="loc_invest_InvestmentDomain_A9E8F3FC6BA184E3D846B0A3E245BF0F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_A9E8F3FC6BA184E3D846B0A3E245BF0F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentAxis_85E60D17B17B2FBA4B1DB0A3E24558FB" xlink:to="loc_invest_InvestmentDomain_A9E8F3FC6BA184E3D846B0A3E245BF0F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_DCA8DC41FA264844404BB0A3E245A930" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentDomain_A9E8F3FC6BA184E3D846B0A3E245BF0F" xlink:to="loc_us-gaap_InterestRateSwapMember_DCA8DC41FA264844404BB0A3E245A930" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForwardContractsMember" xlink:label="loc_us-gaap_ForwardContractsMember_A80F47837D4AB720C759B0A3E24552D3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestRateSwapMember_DCA8DC41FA264844404BB0A3E245A930" xlink:to="loc_us-gaap_ForwardContractsMember_A80F47837D4AB720C759B0A3E24552D3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeByNatureAxis" xlink:label="loc_us-gaap_DerivativeByNatureAxis_3777B83A55D1826626FFB0A3E24580EE" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_DerivativeByNatureAxis_3777B83A55D1826626FFB0A3E24580EE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_060FB1963D76A7198EABB0A3E245D41C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeByNatureAxis_3777B83A55D1826626FFB0A3E24580EE" xlink:to="loc_agnc_DerivativebyNatureDomain_060FB1963D76A7198EABB0A3E245D41C_default" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DerivativebyNatureDomain" xlink:label="loc_agnc_DerivativebyNatureDomain_060FB1963D76A7198EABB0A3E245D41C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeByNatureAxis_3777B83A55D1826626FFB0A3E24580EE" xlink:to="loc_agnc_DerivativebyNatureDomain_060FB1963D76A7198EABB0A3E245D41C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_234785AC8B94F1C75FB1B0A3E245927E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_agnc_DerivativebyNatureDomain_060FB1963D76A7198EABB0A3E245D41C" xlink:to="loc_us-gaap_InterestRateSwapMember_234785AC8B94F1C75FB1B0A3E245927E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_B3D48AF56FE736A4FAF1B0A3E24590C5" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_B3D48AF56FE736A4FAF1B0A3E24590C5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7855C264A107EC1E30D7B0A3E24576AE_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_B3D48AF56FE736A4FAF1B0A3E24590C5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7855C264A107EC1E30D7B0A3E24576AE_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7855C264A107EC1E30D7B0A3E24576AE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_B3D48AF56FE736A4FAF1B0A3E24590C5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7855C264A107EC1E30D7B0A3E24576AE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_F7495A3858B7CE13B39FB0A3E2452E99" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7855C264A107EC1E30D7B0A3E24576AE" xlink:to="loc_us-gaap_InterestRateSwapMember_F7495A3858B7CE13B39FB0A3E2452E99" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_DACD8481D279BE25BD98B0A3E245A8C3" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_DACD8481D279BE25BD98B0A3E245A8C3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_E717916BA070812238E7B0A3E245C3D2_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_DACD8481D279BE25BD98B0A3E245A8C3" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_E717916BA070812238E7B0A3E245C3D2_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_E717916BA070812238E7B0A3E245C3D2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_DACD8481D279BE25BD98B0A3E245A8C3" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_E717916BA070812238E7B0A3E245C3D2" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_DB9B68B05BF0DBFCF219B0A3E2451247" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_E717916BA070812238E7B0A3E245C3D2" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_DB9B68B05BF0DBFCF219B0A3E2451247" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_468471D4E5207D7B7E94B0A3E245EAAD" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_81ABA15CBCDD01323281B0A3E24586AE" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_468471D4E5207D7B7E94B0A3E245EAAD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_4848AFC3BD7CF4B7E74AB0A3E245935B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_468471D4E5207D7B7E94B0A3E245EAAD" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_4848AFC3BD7CF4B7E74AB0A3E245935B_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_4848AFC3BD7CF4B7E74AB0A3E245935B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_468471D4E5207D7B7E94B0A3E245EAAD" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_4848AFC3BD7CF4B7E74AB0A3E245935B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_7ED5E3653AAD424B4BC1B0A3E245435C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_4848AFC3BD7CF4B7E74AB0A3E245935B" xlink:to="loc_us-gaap_AgencySecuritiesMember_7ED5E3653AAD424B4BC1B0A3E245435C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_81EA0AC49D7669BFAE78B0A3E24594A1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_81EA0AC49D7669BFAE78B0A3E24594A1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_69C132D30D9E148D9AB9B0A3E24532E3" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_invest_DerivativeNotionalAmount_69C132D30D9E148D9AB9B0A3E24532E3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_4E8FEEC7EED5BC49EB7CB0A3E2458B97" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_SharePrice_4E8FEEC7EED5BC49EB7CB0A3E2458B97" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_A609DB3DD26AA98664CDB0A3E2455C93" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockValue_A609DB3DD26AA98664CDB0A3E2455C93" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_4004EB90CB2B07C499D2B0A3E245C5E0" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_CommonStockSharesIssued_4004EB90CB2B07C499D2B0A3E245C5E0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_15748EA0623106175B7EB0A3E2458011" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_15748EA0623106175B7EB0A3E2458011" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_81EE70F4CE2EB0859A17B0A3E245BDE7" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_81EE70F4CE2EB0859A17B0A3E245BDE7" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization" xlink:label="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_4FBB5F28991BD995D873B0A3E2454482" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_4FBB5F28991BD995D873B0A3E2454482" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_SpreadOverLibor" xlink:label="loc_agnc_SpreadOverLibor_A7A094291DB374F5D802B0A3E245DBE1" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_agnc_SpreadOverLibor_A7A094291DB374F5D802B0A3E245DBE1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_6AC1D9D5D59B8557EB72B0A3E2458E89" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_6AC1D9D5D59B8557EB72B0A3E2458E89" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_CC8E5ED87630C541349CB0A3E24588B3" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_CC8E5ED87630C541349CB0A3E24588B3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_A0D9EB29267F8DCE7461B0A3E245B59B" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_A0D9EB29267F8DCE7461B0A3E245B59B" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_PreferredStockAuthorizedButNotIssued" xlink:label="loc_agnc_PreferredStockAuthorizedButNotIssued_C34C19B11BD859D5D6EDB0A3E2459577" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_agnc_PreferredStockAuthorizedButNotIssued_C34C19B11BD859D5D6EDB0A3E2459577" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_8E9035FDC606A3219766B0A3E245EEC5" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_8E9035FDC606A3219766B0A3E245EEC5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_D1EE5533C9980570BB9FB0A3E24532AE" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_D1EE5533C9980570BB9FB0A3E24532AE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount_7CA15CAF0D2D1CED2A0EB0A3E2458A06" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount_7CA15CAF0D2D1CED2A0EB0A3E2458A06" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_FBEF77EF71C5E78AB2D9B0A3E2452A1D" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_FBEF77EF71C5E78AB2D9B0A3E2452A1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_C681ED7C89CE006DB297B0A3E2450824" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_C681ED7C89CE006DB297B0A3E2450824" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_E0F94D70E7AB577BE724B0A3E245C743" xlink:type="locator" />
    <definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_E0F94D70E7AB577BE724B0A3E245C743" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_500A2282977E52B27322B0A3E2455AAE" xlink:type="locator" />
    <definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_500A2282977E52B27322B0A3E2455AAE" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalReclassOfOtherComprehensiveIncome" xlink:label="loc_agnc_TotalReclassOfOtherComprehensiveIncome_F1EE084526DA3326D1F4B0A3E245D6B8" xlink:type="locator" />
    <definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_agnc_TotalReclassOfOtherComprehensiveIncome_F1EE084526DA3326D1F4B0A3E245D6B8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge" xlink:label="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_0CC02D4B5EBE2A5F376EB0A3E245D6A3" xlink:type="locator" />
    <definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_0CC02D4B5EBE2A5F376EB0A3E245D6A3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_FBC95F6ED0FDCA62AFD1B0A3E245407E" xlink:type="locator" />
    <definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_FBC95F6ED0FDCA62AFD1B0A3E245407E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_7625E0734AB1A3D88B0EB0A3E2453A09" xlink:type="locator" />
    <definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_7625E0734AB1A3D88B0EB0A3E2453A09" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_EC26E7340E8CF795D07EB0A3E24590F5" xlink:type="locator" />
    <definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_EC26E7340E8CF795D07EB0A3E24590F5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockDividendRatePercentage" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_712543F4AC0F31D333CDB0A3E2459A15" xlink:type="locator" />
    <definitionArc order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_712543F4AC0F31D333CDB0A3E2459A15" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_PreferredStockCapitalSharesReservedForFutureIssuance_4C03DE8BF7B91CD81E9EB0A3E24557C6" xlink:type="locator" />
    <definitionArc order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockCapitalSharesReservedForFutureIssuance_4C03DE8BF7B91CD81E9EB0A3E24557C6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued_FB83FAF0E4DAD966C9E2B0A3E245A21B" xlink:type="locator" />
    <definitionArc order="28" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockSharesIssued_FB83FAF0E4DAD966C9E2B0A3E245A21B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockLiquidationPreference" xlink:label="loc_us-gaap_PreferredStockLiquidationPreference_2DFFBE613A78177F24A1B0A3E245C683" xlink:type="locator" />
    <definitionArc order="29" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_39689F1BCF606C255819B0A3E245EDB3" xlink:to="loc_us-gaap_PreferredStockLiquidationPreference_2DFFBE613A78177F24A1B0A3E245C683" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/StockholdersEquityEquityOfferingsTables" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_44BD41D90517DCF41A59F0C8A5738BBE" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_F53450F501A97F667DB0F0C8A57325AD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_44BD41D90517DCF41A59F0C8A5738BBE" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_F53450F501A97F667DB0F0C8A57325AD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2B61CD541A936C7462A6F0C8A5736F0A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_F53450F501A97F667DB0F0C8A57325AD" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2B61CD541A936C7462A6F0C8A5736F0A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_D2EF1CC8BAD78E27948AF0C8A5732D27_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2B61CD541A936C7462A6F0C8A5736F0A" xlink:to="loc_us-gaap_ClassOfStockDomain_D2EF1CC8BAD78E27948AF0C8A5732D27_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_D2EF1CC8BAD78E27948AF0C8A5732D27" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2B61CD541A936C7462A6F0C8A5736F0A" xlink:to="loc_us-gaap_ClassOfStockDomain_D2EF1CC8BAD78E27948AF0C8A5732D27" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockByClassTextBlock" xlink:label="loc_us-gaap_ScheduleOfStockByClassTextBlock_A433796EC9DA6A453864F0C8A573BAD7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_44BD41D90517DCF41A59F0C8A5738BBE" xlink:to="loc_us-gaap_ScheduleOfStockByClassTextBlock_A433796EC9DA6A453864F0C8A573BAD7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_395EB6166242079E83D3F0C8A573DFC4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_44BD41D90517DCF41A59F0C8A5738BBE" xlink:to="loc_us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_395EB6166242079E83D3F0C8A573DFC4" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/StockholdersEquitySummaryOfFollowOnPublicOfferingsOfCommonStockDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:type="locator" />
    <loc xlink:href="agnc-20140630.xsd#agnc_StockholdersEquityTable" xlink:label="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassAxis" xlink:label="loc_invest_InvestmentSecuritiesClassAxis_CF1FEC4087905F0EEEE4F0C8A536EBE1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:to="loc_invest_InvestmentSecuritiesClassAxis_CF1FEC4087905F0EEEE4F0C8A536EBE1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_74DC6ABC43E3E21844D3F0C8A536A2B5_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_CF1FEC4087905F0EEEE4F0C8A536EBE1" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_74DC6ABC43E3E21844D3F0C8A536A2B5_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentSecuritiesClassDomain" xlink:label="loc_invest_InvestmentSecuritiesClassDomain_74DC6ABC43E3E21844D3F0C8A536A2B5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentSecuritiesClassAxis_CF1FEC4087905F0EEEE4F0C8A536EBE1" xlink:to="loc_invest_InvestmentSecuritiesClassDomain_74DC6ABC43E3E21844D3F0C8A536A2B5" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestRateSwapsMember" xlink:label="loc_agnc_InterestRateSwapsMember_417FDA70213272C5B73FF0C8A5366521" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentSecuritiesClassDomain_74DC6ABC43E3E21844D3F0C8A536A2B5" xlink:to="loc_agnc_InterestRateSwapsMember_417FDA70213272C5B73FF0C8A5366521" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_2682B5D01B81B7460581F0C8A536DDEF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_2682B5D01B81B7460581F0C8A536DDEF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1B43AF9E76C3AC7208ABF0C8A5366762_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_2682B5D01B81B7460581F0C8A536DDEF" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1B43AF9E76C3AC7208ABF0C8A5366762_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1B43AF9E76C3AC7208ABF0C8A5366762" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_2682B5D01B81B7460581F0C8A536DDEF" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1B43AF9E76C3AC7208ABF0C8A5366762" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_146B6243F008D9E1A651F0C8A537CB40" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1B43AF9E76C3AC7208ABF0C8A5366762" xlink:to="loc_us-gaap_InterestRateSwapMember_146B6243F008D9E1A651F0C8A537CB40" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_24F40B07C2957BC898F9F0C8A537D8CD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_24F40B07C2957BC898F9F0C8A537D8CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_365AD52D769B3372AECAF0C8A5375194_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_24F40B07C2957BC898F9F0C8A537D8CD" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_365AD52D769B3372AECAF0C8A5375194_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_365AD52D769B3372AECAF0C8A5375194" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_24F40B07C2957BC898F9F0C8A537D8CD" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_365AD52D769B3372AECAF0C8A5375194" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_E6913C9D97C0D8E90CFBF0C8A537E29E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_365AD52D769B3372AECAF0C8A5375194" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_E6913C9D97C0D8E90CFBF0C8A537E29E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_F51BB1EFC248283C84C0F0C8A5378E79" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_F51BB1EFC248283C84C0F0C8A5378E79" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_FA5BDA50A9D8C434B26BF0C8A53792C3_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_F51BB1EFC248283C84C0F0C8A5378E79" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_FA5BDA50A9D8C434B26BF0C8A53792C3_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_FA5BDA50A9D8C434B26BF0C8A53792C3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_F51BB1EFC248283C84C0F0C8A5378E79" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_FA5BDA50A9D8C434B26BF0C8A53792C3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AgencySecuritiesMember" xlink:label="loc_us-gaap_AgencySecuritiesMember_9ACEAE775BEB25D4FBE8F0C8A537F4CB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_FA5BDA50A9D8C434B26BF0C8A53792C3" xlink:to="loc_us-gaap_AgencySecuritiesMember_9ACEAE775BEB25D4FBE8F0C8A537F4CB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_D283CCAFD643227E5F63F0C8A53771C1" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_agnc_StockholdersEquityTable_A69970B73EF7303B2916F0C8A536FD8A" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_D283CCAFD643227E5F63F0C8A53771C1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_879A5C3EC214715D0458F0C8A53753A0_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_D283CCAFD643227E5F63F0C8A53771C1" xlink:to="loc_us-gaap_EquityComponentDomain_879A5C3EC214715D0458F0C8A53753A0_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_879A5C3EC214715D0458F0C8A53753A0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_D283CCAFD643227E5F63F0C8A53771C1" xlink:to="loc_us-gaap_EquityComponentDomain_879A5C3EC214715D0458F0C8A53753A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_B140242211F82DAD998EF0C8A537D76E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_879A5C3EC214715D0458F0C8A53753A0" xlink:to="loc_us-gaap_CommonStockMember_B140242211F82DAD998EF0C8A537D76E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_39192317D33735FE7E9EF0C8A537B57D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityExpense_39192317D33735FE7E9EF0C8A537B57D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_21C902781A7429FE3E56F0C8A537EE91" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_21C902781A7429FE3E56F0C8A537EE91" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_35D518F8077B35B28C6CF0C8A537D20F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_35D518F8077B35B28C6CF0C8A537D20F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_438FE6368AC66F8ED6CFF0C8A5379871" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_438FE6368AC66F8ED6CFF0C8A5379871" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_357CE268E10A623BCAB6F0C8A5389642" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_ShareBasedCompensation_357CE268E10A623BCAB6F0C8A5389642" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_6C6D973EFA86B317948AF0C8A5387C9F" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_SharePrice_6C6D973EFA86B317948AF0C8A5387C9F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_9A30E0B6A14D22A17546F0C8A538E860" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_CommonStockSharesIssued_9A30E0B6A14D22A17546F0C8A538E860" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_4AA7C400D9ABC659EE89F0C8A538637E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_4AA7C400D9ABC659EE89F0C8A538637E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount_83F9384370FD4C47887EF0C8A538D517" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount_83F9384370FD4C47887EF0C8A538D517" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_32585E4D984FE26AC110F0C8A5383967" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_32585E4D984FE26AC110F0C8A5383967" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_3B56956E09DD64BEB10CF0C8A53806DD" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_3B56956E09DD64BEB10CF0C8A53806DD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_B89DAB4CB8FEAF93E872F0C8A538084F" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_B89DAB4CB8FEAF93E872F0C8A538084F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount_9609C7BD5CF0F003B022F0C8A538EF66" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount_9609C7BD5CF0F003B022F0C8A538EF66" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_68BDC9FC594967D64C61F0C8A538C11A" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_68BDC9FC594967D64C61F0C8A538C11A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_AFADDCDC911D7AA8E1C8F0C8A538A62E" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_AFADDCDC911D7AA8E1C8F0C8A538A62E" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization" xlink:label="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_4C4FFCEAF6CF85CCD19DF0C8A538F2C0" xlink:type="locator" />
    <definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_agnc_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecurityReversalOfPriorPeriodUnrealizedGainAndLossesOnRealization_4C4FFCEAF6CF85CCD19DF0C8A538F2C0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_A1DAD96F570312BB7084F0C8A538587F" xlink:type="locator" />
    <definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_A1DAD96F570312BB7084F0C8A538587F" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_TotalReclassOfOtherComprehensiveIncome" xlink:label="loc_agnc_TotalReclassOfOtherComprehensiveIncome_87AE53D094DB231FF8DBF0C8A538D669" xlink:type="locator" />
    <definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_agnc_TotalReclassOfOtherComprehensiveIncome_87AE53D094DB231FF8DBF0C8A538D669" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_NetCurrentPeriodOtherComprehensiveIncome" xlink:label="loc_agnc_NetCurrentPeriodOtherComprehensiveIncome_2FC8E47C327C0E24CF22F0C8A538C3FC" xlink:type="locator" />
    <definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_agnc_NetCurrentPeriodOtherComprehensiveIncome_2FC8E47C327C0E24CF22F0C8A538C3FC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_4765A4EFA2FEEFCB4AC9F0C8A538856C" xlink:type="locator" />
    <definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_4765A4EFA2FEEFCB4AC9F0C8A538856C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_839B065827BC6693FF1EF0C8A538E9AD" xlink:type="locator" />
    <definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_839B065827BC6693FF1EF0C8A538E9AD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_6C96DBA4703BF9CC4711F0C8A5388B73" xlink:type="locator" />
    <definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_6C96DBA4703BF9CC4711F0C8A5388B73" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_FB45C12FB0061B7B69FDF0C8A5387873" xlink:type="locator" />
    <definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_FB45C12FB0061B7B69FDF0C8A5387873" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_C982D83FEAB4456B2225F0C8A5396E1D" xlink:type="locator" />
    <definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_C982D83FEAB4456B2225F0C8A5396E1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge" xlink:label="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_9E8FBA52B7FFF077EB21F0C8A53909B5" xlink:type="locator" />
    <definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge_9E8FBA52B7FFF077EB21F0C8A53909B5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_ECEB95FB10EB0D2EDB22F0C8A5392243" xlink:type="locator" />
    <definitionArc order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6914B220ABE73022F997F0C8A5373765" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_ECEB95FB10EB0D2EDB22F0C8A5392243" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/SubsequentEventDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/SubsequentEventNotes" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/SubsequentEventTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/SummaryOfSignificantAccountingPolicies" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/SummaryOfSignificantAccountingPoliciesDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.agnc.com/role/SummaryOfSignificantAccountingPoliciesPolicy" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_56A66A14454C9DE6D73DF0C8A5B1533E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_56A66A14454C9DE6D73DF0C8A5B1533E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_8A85C3B5F49448DA3E5EF0C8A5B2E7EA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_56A66A14454C9DE6D73DF0C8A5B1533E" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_8A85C3B5F49448DA3E5EF0C8A5B2E7EA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_F408B79E09D277FCCD41F0C8A5B2B54D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_8A85C3B5F49448DA3E5EF0C8A5B2E7EA" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_F408B79E09D277FCCD41F0C8A5B2B54D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_F408B79E09D277FCCD41F0C8A5B2B54D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_8A85C3B5F49448DA3E5EF0C8A5B2E7EA" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_F408B79E09D277FCCD41F0C8A5B2B54D" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember" xlink:label="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_4A7B6971BC91A1CE49A2F0C8A5B2B74B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_F408B79E09D277FCCD41F0C8A5B2B54D" xlink:to="loc_agnc_DiscontinuationOfElectionToAccountForInterestRateSwapsAsDesignatedCashFlowHedgesMember_4A7B6971BC91A1CE49A2F0C8A5B2B74B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:label="loc_us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_548606865BE737D43BCCF0C8A5B28134" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_548606865BE737D43BCCF0C8A5B28134" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="loc_us-gaap_UseOfEstimates_B0A378DBB3AD2C74063CF0C8A5B2C31A" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_UseOfEstimates_B0A378DBB3AD2C74063CF0C8A5B2C31A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="loc_us-gaap_EarningsPerSharePolicyTextBlock_0C3BE655CB481B6D2309F0C8A5B23CB9" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_EarningsPerSharePolicyTextBlock_0C3BE655CB481B6D2309F0C8A5B23CB9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:label="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_7824B6DB9A02EC106B8BF0C8A5B2CCEC" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_7824B6DB9A02EC106B8BF0C8A5B2CCEC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="loc_us-gaap_CashAndCashEquivalentsPolicyTextBlock_3E82ED05E26E9A936F6BF0C8A5B266D1" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_CashAndCashEquivalentsPolicyTextBlock_3E82ED05E26E9A936F6BF0C8A5B266D1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:label="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_C72939A248881F62E7CEF0C8A5B2BA9F" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_C72939A248881F62E7CEF0C8A5B2BA9F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentPolicyTextBlock" xlink:label="loc_us-gaap_InvestmentPolicyTextBlock_738D42BAC61643313818F0C8A5B24833" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_InvestmentPolicyTextBlock_738D42BAC61643313818F0C8A5B24833" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_InterestIncomePolicyTextBlock" xlink:label="loc_agnc_InterestIncomePolicyTextBlock_3A6F103859DDA2D74E97F0C8A5B2C0E2" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_agnc_InterestIncomePolicyTextBlock_3A6F103859DDA2D74E97F0C8A5B2C0E2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepurchaseAndResaleAgreementsPolicy" xlink:label="loc_us-gaap_RepurchaseAndResaleAgreementsPolicy_1A01467C136C9E5EA0DEF0C8A5B29866" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_RepurchaseAndResaleAgreementsPolicy_1A01467C136C9E5EA0DEF0C8A5B29866" xlink:type="arc" />
    <loc xlink:href="agnc-20140630.xsd#agnc_ReverseRepurchaseAgreementsPolicyPolicyTextBlock" xlink:label="loc_agnc_ReverseRepurchaseAgreementsPolicyPolicyTextBlock_7B71A1E74DC592EECC87F0C8A5B2F831" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_agnc_ReverseRepurchaseAgreementsPolicyPolicyTextBlock_7B71A1E74DC592EECC87F0C8A5B2F831" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ManagementAndInvestmentAdvisoryFeesPolicy" xlink:label="loc_us-gaap_ManagementAndInvestmentAdvisoryFeesPolicy_7E9DA84F3AA007E44576F0C8A5B2C154" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_ManagementAndInvestmentAdvisoryFeesPolicy_7E9DA84F3AA007E44576F0C8A5B2C154" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativesPolicyTextBlock" xlink:label="loc_us-gaap_DerivativesPolicyTextBlock_F7C5E7845034735996D0F0C8A5B2C969" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_DerivativesPolicyTextBlock_F7C5E7845034735996D0F0C8A5B2C969" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:label="loc_us-gaap_ConsolidationVariableInterestEntityPolicy_F916B27EB329C334AD3CF0C8A5B23309" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_ConsolidationVariableInterestEntityPolicy_F916B27EB329C334AD3CF0C8A5B23309" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock_D296406490E56A565B46F0C8A5B32AB4" xlink:type="locator" />
    <definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_IncomeTaxPolicyTextBlock_D296406490E56A565B46F0C8A5B32AB4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription_57ACA1E9FB2DB80F2B3CF0C8A5B3D7F9" xlink:type="locator" />
    <definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_1CAB9BAB4C7E763589C7F0C8A5B2DDCC" xlink:to="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription_57ACA1E9FB2DB80F2B3CF0C8A5B3D7F9" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.agnc.com/role/UnauditedInterimConsolidatedFinancialStatements" xlink:type="extended" />
</linkbase>
