The projected costs for F-35 Joint Strike Fighter jets has by nearly 10% in the past three years, or about $51 billion, according to a declassified report by the U.S. Dept of War. The reasons for the increase are more than rising costs for the aircraft, and include more expensive engines, software and technology updates, spare parts acquisition, and general upkeep costs to maintain fleet readiness.
Currently, the Pentagon estimates the total cost of the F-35 program at $536 billion, up from its previous projection of $485 billion. The new total is not a near-term spending estimate, but rather a projection of the total acquisition cost of the U.S. F-35 program over the Department’s planned procurement period, through 2049.
The F-35 is a series of single-engine, Stealth-enabled aircraft deployed for ground attack and combat, and available in three variants. It’s the most expensive defense program, supplying aircraft to the U.S. Air Force, U.S. Marine Corps, U.S. Navy, and defense forces of 19 allied nations.
Lockheed Martin is the lead contractor for the program, which also includes Pratt & Whitney as the turbofan engine suppliers, BAE Systems Northrop Grumman, Raytheon, Rolls-Royce, L3 Harris Technologies, Collins Aerospace, and several more major system suppliers.
The jets have been in production since 2006, and over 1,345 aircraft of all three variants have been build as of August 2026.
In September 2025, the Pentagon and Lockheed Martin finalized terms for Lots 18 and 19 of the program, agreements totaling $24 billion for delivery of up to 296 F-35s. They are the largest production contracts to-date in the 25-year history of program. Based on that agreement the current unit cost for the F-35 is about $105 million.
But in addition to the acquisition and technology update costs, the F-35 has accumulated a record for frequent maintenance requirements. Earlier this year the Pentagon released an inspector general’s report that concluded held Lockheed Martin accountable for poor performance in sustainment activities for the stealth fighter aircraft. Despite the report’s conclusion that confirmed the Joint Strike Fighter aircraft has achieved only a 50% readiness rate, the contractor was paid $1.7 billion without any fees or adjustments.
