Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Fort Worth, Texas, is awarded a $611,270,079 modification (P00005) to a previously awarded cost-plus-fixed-fee, cost-plus-incentive-fee contract (N0001923C0009). This modification exercises options to procure development of Multi-Ship Infrared Search and Track Increment 2 hardware and Band 5 Radar Warning Receiver hardware in support of Lot 18 U.S. Reprograming Lab Development; Lot 18 Australia, Canada, and the United Kingdom Reprogramming Lab Development; Lot 18 Norway and Italy Reprogramming Lab Development; Lot 18 Denmark, Netherlands, and Foreign Military Sales (FMS) mission data file updates; and F-35 In a Box development and licensing for the F-35A/B/C aircraft. Work will be performed in Fort Worth, Texas (60%); Nashua, New Hampshire (16%); Baltimore, Maryland (9%); Orlando, Florida (5.5%); Torrance, California (2%); San Diego, California (2%); El Segundo, California (2%); Northridge, California (1%); Clearwater, Florida (1%); Buffalo, New York (1%); and Tucson, Arizona (0.5%), and is expected to be completed in June 2026. Fiscal 2024 research, development, test and evaluation (Navy) funds in the amount of $5,724,622; fiscal 2024 research, development, test, and evaluation (Air Force) funds in the amount of $5,724,623; FMS customer funds in the amount of $1,201,206; and non-Department of Defense participants funds in the amount of $15,527,961, will be obligated at the time of award, none of which will expire at the end of the current fiscal year. Naval Air Systems Command, Patuxent River, Maryland, is the contracting activity.