Inflation and rising costs for critical upgrades are swelling the price of the F-35 fighter, according to a newly released acquisition report on the fifth-generation jet.
The total estimated acquisition cost for the F-35—covering all the airframes and engines the U.S. government plans to buy—is now $536.2 billion, according to the latest modernized selected acquisition report the Pentagon released this month. That is $51 billion more than the $485.2 billion price tag recorded in the previous 2023 report, which represents more than 10 percent growth.
Other metrics included in the acquisition report show similar cost growth, such as the unit recurring flyaway cost—essentially the cost to produce one jet and its engine:
- For the Air Force’s F-35A, the new flyaway cost is $78 million apiece in 2012 dollars, up 7.3 percent from the $72.7 million recorded in the last report.
- For the F-35C carrier variant, flown by the Navy and U.S. Marine Corps, the new flyaway cost is $93.4 million in 2012 dollars, up 6.6 percent from the $87.65 million in the 2023 report
- For the Marine Corps’ F-35B short takeoff and vertical landing variant, the most complex version, the flyaway cost is now $110.3 million in 2012 dollars, up 10.5 percent from $99.78 million.
The F-35 Joint Program Office, in response to queries from Air & Space Forces Magazine, declined to share the cost per variant for the latest F-35 lots in current-year dollars, saying that information is considered CUI, or controlled unclassified information, and is not releasable.
Nevertheless, the JPO did acknowledge the rise in costs and detailed some of the causes.
Research, development, test, and evaluation costs—which make up part of the overall total acquisition costs—have risen about $19 billion to $106.6 billion. The JPO said that growth reflects a refined estimate of the F-35’s Power Thermal Management Upgrade program to account for updated requirements and assumptions.
The F-35 program has also refined the schedule for the jet’s Block 4 modernization—a sweeping slate of upgrades intended to boost the F-35’s weapons, sensors, sensor fusion, and other capabilities—and engine core upgrade and power thermal management modernization efforts, which has added years and costs to the program, the JPO said.
The refinement of capability estimates for Block 4 accounted for about $900 million of that $19 billion growth in RDT&E costs, the JPO said.
The acquisition report said the F-35 program is prioritizing the delivery of 55 critical Block 4 capabilities, including kill chain enhancements for the F-35’s air superiority and suppression of enemy air defenses missions, and the integration of vital new weapons.
The JPO attributed another nearly $32 billion in procurement cost growth to incorporating the production costs of the F-35’s upcoming APG-85 radar, growth in production support costs, addition of the power thermal management upgrade production requirement, and incorporation of contractors’ actual costs, and the negotiated contract price of the F-35’s Lots 18 and 19.
In September 2025, the Pentagon announced the F-35 JPO and Lockheed Martin had struck a final deal for Lots 18 and 19, to buy 296 aircraft for $24.29 billion. In April, the JPO and Pratt & Whitney announced deals worth a combined $6.6 billion for engines for Lots 18 and 19. Taken together, that points to an average cost across all variants of $104.4 million or so.
The report also pointed to rising inflation and material costs as other factors placing upward pressure on the F-35’s price tags.
The military plans to push some F-35 purchases into future “out-years” beyond the current budget cycle, the JPO said. The Marine Corps is also planning to shift some of its purchases away from F-35Bs and toward the carrier-based F-35Cs, the JPO said. Because the Marines will be buying F-35Cs further in the future than it had planned to buy F-35Bs, those carrier-based jets will be more expensive due to inflation and rising maintenance costs, further contributing to the program’s rising costs.
In the MSAR’s executive summary, the Pentagon called the F-35 program a “mature enterprise” with more than 1,200 jets operating in 20 nations, which is now focusing on long-term strategies for enhancing capabilities and bringing sustainment costs down. The report also pointed to progress made by the program, including the program entering into full-rate production in March 2024, and fielding aircraft with enhanced Technology Refresh 3 hardware that will pave the way for Block 4.
“The growing global demand speaks for itself,” the Pentagon said in the report. “The F-35’s value proposition is unmatched.”
Lockheed Martin, the primary manufacturer of the F-35, said in a statement to Air & Space Forces Magazine that the new report reflects a shift in the program’s focus toward modernizing the jet to take full advantage of its capabilities.
“The latest MSAR report shows the combat-proven F-35 program moving into full-rate production, resuming high-volume development deliveries and growing globally,” Mireya Villarreal, Lockheed’s spokesperson on the F-35 program, said in an email. “It also shows that the hard work has shifted from proving the basic aircraft to executing major modernizaiton, improving fleet readiness, and controlling long-term sustainment and integration costs.”