Lockheed Martin will build up to 296 F-35s as part of Lots 18 and 19, with first deliveries in 2026.
Lockheed Martin and the F-35 Joint Program Office (JPO) announced they reached a final agreement for the Production Lots 18 and 19, which will see the company building up to 296 F-35s. As part of the contract, F-35s will be produced for the U.S. services, international partners and Foreign Military Sales (FMS) customers, with first deliveries in 2026.
“The F-35 Lot 18-19 contract represents continued confidence in the most affordable and capable fighter aircraft in production today,” said Chauncey McIntosh, Vice President and General Manager of the F-35 Lightning II program at Lockheed Martin. “We are proud to support our customers and further solidify the F-35’s role in enabling peace through strength.”
Lots 18 and 19
Lockheed Martin was awarded in December 2024 a first undefinitized contract for Lot 18, worth $11.8 billion, to produce a total of 145 F-35s by June 2027. This contract was followed in August 2025 by a $2.9 billion contract to Pratt & Whitney for 141 F135 engines to be used on Lot 18 aircraft.
According to the Lot 18 contract notice, the 145 jets include 48 F-35A aircraft for the Air Force, 16 F-35B aircraft and five F-35C aircraft for the Marine Corps, 14 F-35C aircraft for the Navy, 15 F-35A aircraft and one F-35B aircraft for F-35 non-U.S. DoD program partners, and 39 F-35A aircraft and seven F-35B aircraft for Foreign Military Sales (FMS) customers.
The new contract modification awarded on Sept. 29, 2025, worth $12.5 billion, increased Lot 18 to 148 aircraft and added 148 F-35s as part of Lot 19. The latter include 40 F-35A aircraft for the Air Force, 12 F-35B and eight F-35C aircraft for the Marine Corps, nine F-35C aircraft for the Navy, 13 F-35A and two F-35B aircraft for F-35 cooperative program partners, and 52 F-35A and 12 F-35B aircraft for Foreign Military Sales (FMS) customers.
The contract notice further adds that the production of Lot 19 is expected to be completed in August 2028. A contract for the engines needed by Lot 19 has not yet been awarded.
The Cost
Summing up the values of the December 2024 and September 2025 contracts, the total value of the combined Lots 18 and 19 is approximately $24.3 billion. Considering the total of 296 aircraft, the average price of an airframe would be just shy of $82.1 million, to which the price of the engine still needs to be added. For Lot 18, this would mean an additional $20.5 million for each jet.
The prices of each variant as part of the two new lots have not been disclosed yet. Previously, for Production Lots 15 through 17, the JPO said the average flyaway cost of an F-35A was $82.5 million, $109 million for an F-35B, and $102.1 million per F-35C.
In the press release, Lockheed Martin said “the increase in price per jet in Lot 18-19 from previous years was less than the rate of inflation.” Breaking Defense previously reported that defense officials said the “significant price increase” of Lot 18 is “primarily attributed to inflation, significant global price increases for raw materials, and supply chain disruptions.”
The report surfaced as negotiations for the contract were still ongoing. The publication quoted a statement from the JPO, which anticipated the wording found in the latest press release: “The global economy 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.”
Additional F-35 Contracts
Together with the Lots 18 and 19 contract, the Pentagon awarded additional contracts for the F-35 Lightning II on Sept. 29, 2025. Among these is a $137.2 contract “to provide diminishing manufacturing sources and engineering change proposals implementation and integration in support of updating configurations for F-35 production aircraft Lot 17.”
Another contract, worth $101,1 million, has been awarded for the “advanced procurement of parts susceptible to anticipated diminishing manufacturing sources and material shortages events in support of F-35 production and sustainment.”
Finally, a $11,6 million contract was awarded for the “redesign of the Sensor Electronics circuit card assembly in support of resolving the NextGen Electro Optical Distributed Aperture System diminishing manufacturing sources and material shortages redesign.” This refers to the upgraded DAS system, which was planned to replace the original system since 2023 for Lot 15 aircraft onwards.
