Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Fort Worth, Texas, is awarded a not-to-exceed $472,469,642 undefinitized contract modification (P00041) to previously awarded cost-plus-incentive-fee contract N00019-19-C-0010. This modification adds scope to further develop and integrate three unique weapons capabilities through system functional review to development test complete on the F-35A and F-35B aircraft for the governments of the United Kingdom and Italy. Work will be performed in Fort Worth, Texas (39%); Stevenage, United Kingdom (36%); Samlesbury, United Kingdom (12%); El Segundo, California (4%); Baltimore, Maryland (3%); Harlow, United Kingdom (2%); Tucson, Arizona (2%); Orlando, Florida (1%); and Amityville, New York (1%), and is expected to be completed in March 2026. Non-Department of Defense participant funds in the amount of $116,462,707 will be obligated at time of award, none of which will expire at the end of the current fiscal year. The Naval Air Systems Command, Patuxent River, Maryland, is the contracting activity. (Awarded June 18, 2021)