F-35 Deal for Lots 18 and 19 Covers Nearly 300 Fighters at $24.3 Billion

The F-35 Joint Program Office and Lockheed Martin have struck a final, “definitized” deal for Lots 18 and 19, covering nearly 300 fighter jets a total cost of nearly $24.3 billion.

The Sept. 29 contract modification, worth $12.5 billion, provides the final details on Lot 18 and includes “scope for the production and delivery” of Lot 19. It builds on an $11.8 billion agreement between the Pentagon and Lockheed in December 2024 for Lot 18.

That puts the final price of the two lots, split evenly between 296 aircraft, at $24.29 billion. That puts the average cost of the airframe across all variants and customers at $82.4 million.

The JPO was not immediately prepared to break down the unit cost by variant, but typically, the Air Force F-35A model is significantly less costly than the much more complex short-takeoff/vertical landing F-35B and larger, carrier-capable F-35C for the Navy.

The average cost also does not include the F-35’s F135 engines, which are contracted separately with RTX’s Pratt & Whitney and provided to Lockheed as government-furnished equipment. The JPO said the engine contract will be announced separately.

A Lockheed Martin spokesperson said the “increase in price per jet in Lot 18-19 from previous years was less than the rate of inflation.” The contract is of a “fixed-price incentive (firm-target), firm-fixed-price, cost-plus-fixed-fee” type.

The first aircraft in the new lots are slated to to start delivering in 2026. Lot 20 is expected to be negotiated under a multiyear production contract possible now that the F-35 is considered in “full rate production.”

The contract comes ten months after the two parties announced they had a “handshake deal” on the two production lots, and they predicted at that time that the finalized contract would be signed by spring 2025. Negotiations dragged on, though, and the JPO announced the two lots would be combined into a single contract negotiation during the summer. The deal needed to be struck before the end of the fiscal year, which ends Sept. 30. Before the handshake deal, bargaining had been underway for several years.

A JPO spokesman said the price per airplane, or “unit recurring flyaway costs increased; however, [the] total settlement price is beneath relevant inflation indices increases.” He added that the “cost per aircraft varies as a function of quantity, variant mix, and economic forces.”

The global economy, the JPO spokesman said, “has experienced significant inflationary pressures since the Lot 15-17 contract was signed. Nevertheless, the F-35 Joint Program Office and Lockheed Martin arrived at a cost per air vehicle below the relevant inflation indices, underscoring the F-35 enterprise’s commitment to control costs. Adjusted for inflation, the cost per air vehicle is consistent with the cost of those in Lot 15-17.”

The contract covers not only aircraft for the U.S, Air Force, Marine Corps, and Navy, but international partners and Foreign Military Sales customers.

Lot 19 includes:

40 F-35As for the Air Force
12 F-35Bs and eight F-35Cs for the Marine Corps
Nine F-35Cs for the Navy
13 F-35As and two F-35Bs for program partners
52 F-35As and 12 F-35Bs for foreign military sales customers

Chancey McIntosh, Lockheed’s vice president and general manager of the F-35, said the Lot 18-19 contract “represents continued confidence in the most affordable and capable fighter aircraft in production today.”

Lockheed said more than 1,230 F-35s are in service worldwide with 12 nations and the type has flown more than one million hours.