Press Release

Shareholder Call Scheduled for July 30

BETHESDA, Md., July 24 /PRNewswire-FirstCall/ -- American Capital Agency Corp. ("AGNC" or the "Company") (Nasdaq: AGNC) announced today it will report second quarter 2008 earnings on Tuesday, July 29, 2008. AGNC invites shareholders, prospective shareholders and analysts to attend the AGNC Shareholder Call on Wednesday, July 30, 2008 at 10:00 am EDT. The dial in number will be (888) 428-4476. International callers should dial +1 (612) 288-0337. Please advise the operator you are dialing in for the AGNC Shareholder Call.

Point your browser to www.AGNC.com and click on the Q2 2008 Shareholder Call Slide Show button.

BEFORE THE CALL:

REVIEW SLIDE PRESENTATION IN ADVANCE OF THE SHAREHOLDER CALL

The quarterly shareholder presentation includes a slide presentation to accompany the call that participants may download and print prior to the call. You may wish to take the time to review the slides in advance of the Shareholder Call.

DURING THE CALL:

VIEW STREAMING SLIDE PRESENTATION DURING THE SHAREHOLDER CALL During the Shareholder Call you may watch and listen to the webcast or listen to the Shareholder Call by phone and step through the slides at your own pace.

AFTER THE CALL:

LISTEN AND VIEW AUDIO SLIDE PRESENTATION AFTER THE CALL

The audio of the Shareholder Call combined with the slide presentation will be made available on our website www.AGNC.com after the call on July 30.

AUDIO ONLY PRESENTATION AVAILABLE AFTER THE SHAREHOLDER CALL:

There will be a phone recording available from 12:30 pm Wednesday, July 30, 2008 until 11:59 pm Thursday, August 14, 2008. If you are interested in hearing the recording of the presentation, please dial (800) 475-6701. International callers may dial +1 (320) 365-3844. The access code for both domestic and international callers is 952934.

For further information or questions, please do not hesitate to call our Investor Relations Department at (301) 968-9300 or send an email to [email protected].

ABOUT AGNC

AGNC is a real estate investment trust ("REIT") formed in 2008 to invest exclusively in single-family residential mortgage pass-through securities and collateralized mortgage obligations for which the principal and interest payments are guaranteed by a U.S. Government agency or a U.S. Government- sponsored entity. The Company is externally managed and advised by an affiliate of American Capital, Ltd. For further information, please refer to www.AGNC.com.

ABOUT AMERICAN CAPITAL

American Capital (Nasdaq: ACAS), with $21 billion in capital resources under management(1), is the only private equity fund and the largest alternative asset management company in the S&P 500. American Capital, both directly and through its global asset management business, originates, underwrites and manages investments in private equity, leveraged finance, real estate and structured products. American Capital was founded in 1986 and currently has 12 offices in the U.S. and Europe. For further information, please refer to www.ACAS.com.

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements. Forward-looking statements are not guarantees of future performance and are subject to various factors and uncertainties in predicting future results and conditions, including changes in interest rates, changes in the yield curve, changes in prepayment rates, the availability and terms of financing, changes in the market value of our assets, general economic conditions and market conditions.

Persons considering an investment in AGNC should consider the investment objectives, risks and charges and expenses of AGNC carefully before investing. Such information and other information about AGNC is available in AGNC's Registration Statement on Form S-11 filed with the Securities and Exchange Commission. Copies are available on the SEC's website, www.sec.gov. Prospective investors should read such material carefully before investing. The links to third-party websites referenced herein are furnished for informational purposes only. They should not be considered as endorsements or recommendations. Neither AGNC nor any of its affiliates has control over or is affiliated with such third-party websites, and does not take responsibility for their suitability or quality.

(1) Capital resources under management is an estimate of internally and externally managed assets and available capital resources as of May 31, 2008 and does not include any fair value adjustments subsequent to March 31, 2008.

SOURCE American Capital Agency Corp.

CONTACT:
Amanda Cuthbertson, Director, Investor Relations, American Capital
or Pete Deoudes, Director, Equity Capital Markets, American Capital, +1-301-968-9300
Web site: http://www.americancapital.com
http://www.AGNC.com
http://www.ACAS.com