Lockheed Martin won a $991.1 million contract from the U.S. Department of War.
The company will deliver 432 modification kits for the F-35 Lightning II fighter jet fleet.
Block 4 upgrades will enhance electronic warfare capabilities and target recognition.
The modification kits also increase the aircraft's missile capacity.
Recipients include the U.S. Air Force, Marine Corps, and Navy.
Foreign military sales customers and partner nations will also receive the upgrades.
Lockheed also secured $61 million to design and build a next-generation Patriot missile launcher prototype.
Work on the Patriot prototype is expected to run through May 2027.