Lockheed Martin Aeronautics Co., Fort Worth, Texas, is being awarded a $542,225,679 firm-fixed-price indefinite-delivery/indefinite-quantity contract for ancillary mission equipment (AME) and associated AME initial spares in support of Lot 13 F-35 Lightning II aircraft for the Air Force, Marine Corps, Navy, non-U.S. Department of Defense (DoD) participants, and Foreign Military Sales (FMS) customers. Work will be performed in Fort Worth, Texas, and is expected to be completed in May 2023. Fiscal 2018 and 2019 aircraft procurement (Navy, Marine Corps, and Air Force,); non-U.S. DoD participant, and FMS funds in the amount of $437,333,989 will be obligated at time of award, none of which will expire at the end of the current fiscal year. This contract was not competitively procured pursuant to Federal Acquisition Regulation 6.302-1. The Naval Air Systems Command, Patuxent River, Maryland, is the contracting activity (N0001919D0015).