The projected expense for Lockheed Martin's F-35 has increased by roughly $51 billion since late 2023, marking a 10% jump. The increase stems from software updates, readiness needs, spare parts, and engine power upgrades.
The effort, launched in October 2001, was initially expected to cost $233 billion and has frequently been called one of the most advanced military programs. That acquisition total is separate from the money needed for operations and support.
The F-35 program has been running for more than two decades, and its acquisition cost has grown well beyond the $233 billion projected at the start. The latest $536 billion estimate covers the remaining planned U.S. aircraft, engines, and related equipment, while operations and support are expected to add $1.5 trillion over roughly nine decades. The Block 4 upgrade package, which includes 55 improvements that have fallen behind schedule, accounts for part of the increase.
The F-35, developed by Lockheed Martin with significant subcontractors such as Northrop Grumman, has become the backbone of U.S. tactical aviation plans. Its development has seen repeated schedule slips and technical hurdles, from flight-control software to helmet display issues. These challenges have fueled ongoing debates among lawmakers and defense analysts about whether the program's enormous price tag delivers proportional capability. Despite the criticism, the F-35 is still considered essential for future air superiority, with plans to operate the fleet for decades.
Program officials said in a statement that they are tracking the acquisition increase.
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The revised estimate also reflects a decision to buy fewer F-35B short-takeoff and vertical-landing jets for the Marine Corps and more F-35C carrier-based models, which are more expensive. It also accounts for the production cost of the APG-85, a classified high-performance radar made by Northrop Grumman, and for final terms on the 18th and 19th production lots.
Additionally, the program office cited a "refinement" of estimates for the Block 4 package - a set of 55 upgrades that have fallen significantly behind their scheduled timeline - based on recent contractor performance. That refinement increased the estimate by $900 million.
Part of the added money will go toward additional spare parts intended to boost readiness. This year, senior Air Force leaders told Congress, "Poor fleet readiness, stemming from inadequate sustainment and a lack of spare parts, continues as a major worry." A Lockheed Martin representative pointed questions to the program office.
The $536 billion acquisition estimate does not include the $1.5 trillion projected for decades of operations and support.
The program office's report said the commonly cited $2 trillion figure does not tell the whole story. The estimate spans about nine decades and encompasses the aircraft, powerplant, maintenance, and training infrastructure, as well as simulation devices, warfighting networks, prolonged support, and future capability development. Even fuel and the people who maintain the aircraft are included in the reported figures.
By late July, 872 of the 2,470 U.S. aircraft planned had been delivered. The acquisition estimate could rise further if testing finds new problems, if more spare parts are required, or if new technology is added.