Securities of the Fund may only be sold by offering the Fund’s Prospectus and Summary Prospectus. You should consider the investment objectives, risks, charges and expenses of the Fund carefully before investing. The Prospectus and Summary Prospectus contains this and additional information regarding the Fund. To obtain a Prospectus and Summary Prospectus, please contact your Financial Advisor, call 1-800-967-9009 or visit www.americanbeaconfunds.com. The Prospectus and Summary Prospectus should be read carefully before investing.

IMPORTANT INFORMATION:

There is no guarantee that the investment objectives will be met. Indices are unmanaged and one cannot invest directly in an index. Investing in the securities of mid-capitalization companies involves greater risk and the possibility of greater price volatility than investing in larger capitalization and more established companies. Performance shown prior to the inception of the Institutional Class is that of the AMR Class, which had a similar expense structure and performance to the Institutional Class. Performance shown prior to the inception of the Investor Class is that of the AMR Class to 11/30/05 and the Institutional Class from 11/30/05 to 2/28/06. The returns have not been adjusted for any difference between the fees and expenses of the Investor Class and the historical fees and expenses of the AMR and Institutional Classes. Because the AMR and Institutional Classes both had lower expenses, their performance was better than the Investor Class would have realized during the same period. Performance shown prior to the inception of the Advisor Class is that of the AMR Class to 11/30/05, the Institutional Class from 11/30/05 to 2/28/06, and the Investor Class from 2/28/06 to 6/29/07. The returns have not been adjusted for any difference between the fees and expenses of the Advisor Class and the historical fees and expenses of the AMR, Institutional, and Investor Classes. Because the AMR, Institutional, and Investor Classes had lower expenses, their performance was better than the Advisor Class would have realized during the same period. Performance shown prior to the 3/1/10 inception of the Y Class is that of the AMR Class (formerly the Institutional Class of the Fund) from 6/30/04 to 11/30/05 and the Institutional Class from 11/30/05 to 3/1/10. The returns have not been adjusted for any difference between the fees and expenses of the Y Class and the historical fees and expenses of the AMR and Institutional Classes. Because the AMR and Institutional Classes both had lower expenses, their performance was better than the Y Class would have realized during the same period. A portion of the fees charged to the Y Class of the Fund has been waived. Performance prior to waiving fees was lower than the actual returns shown. A portion of the fees charged to the Institutional and Investor Classes has been waived since 2007 and 2006, respectively. A portion of the fees charged to the Advisor Class has been waived since its inception. Performance of the Institutional, Investor, and Advisor Classes prior to waiving fees was lower than the actual returns shown for the respective periods that waivers were in effect. Performance shown prior to the 5/17/10 inception of the A Class is that of the Investor Class. The returns have not been adjusted for any difference between the fees and expenses of the A Class and the historical fees and expenses of the Investor Class. Because the Investor Class had lower expenses, its performance was better than the A Class would have realized during the same period. * Annualized. ** The Lipper Mid-Cap Value Funds Index tracks the results of the 30 largest mutual funds in the Lipper Mid-Cap Value Funds category. Lipper is an independent mutual fund research and ranking service. *** The Russell Midcap Value Index is an unmanaged index of those stocks in the Russell Midcap Index with lower price-to-book ratios and lower forecasted growth values. The P/E Ratio of a stock is calculated by dividing the current price by forecasted twelve-month earnings per share. The P/B Ratio of a stock is calculated by dividing the current price by book value per share. R-squared (R2) is the percentage of the Fund’s three-year return that is explained by movements in its benchmark index. Alpha is a measure of the Fund’s expected performance versus the benchmark, adjusted for relative risk. Beta is a measure of the Fund’s volatility versus the benchmark. Sharpe Ratio is a measure of the Fund’s return per unit of total risk. Standard Deviation is a measure of the historical volatility of the Fund’s returns. Maximum Sales Charge is the maximum front-end sales charge (load) imposed on purchases (as a % of offering price).

Distributed by Foreside Fund Services, LLC. American Beacon Funds and American Beacon Mid-Cap Value Fund are service marks of American Beacon Advisors, Inc. Russell Midcap® and Russell Midcap® Value Indices are registered trademarks of Frank Russell Company.