The F-35 Joint Program Office is struggling to keep track of billions of dollars worth of spare parts for the fifth-generation fighter, government auditors said in a new report—and it still can’t find $85 million in parts that have been lost for years.
The Pentagon does not maintain complete records tracking its worldwide pool of roughly 26 million spare F-35 parts that are collectively worth about $31 billion, the Government Accountability Office said in a report released Nov. 9. What records it has are often inaccurate, incomplete, and don’t reflect real-time changes, the congressional watchdog added.
The report also said the F-35 Joint Program Office has not set up procedures to effectively monitor reports of lost parts, and accountable property officers aren’t given the training or procedures they need to carry out their jobs.
“Unless it implements procedures for monitoring losses, F-35 JPO will not know the full extent of losses of F-35 parts, and its ability to mitigate losses in the future will be decreased, reducing its ability to detect fraud, waste, or theft,” the GAO report states.
This has been a longstanding problem facing the program. A May 2023 GAO report, which was also critical of the F-35 office’s supply tracking, said that more than 1 million spare parts worth $85 million had gone missing over the preceding five years. As of March 2026, the latest report said, those parts have not yet been found.
The F-35 program was set up so all its participants—the U.S. Air Force, Navy, and Marine Corps, as well as multiple foreign countries that are either international partners or customers buying the jet—share a common pool of spare parts such as engines, tires, support equipment, bolts, and screws.
Program officials told GAO auditors that the $31 billion estimate for the global spares pool is probably an undercount, because so many F-35 parts are excluded from the official tally or missing.
The F-35 program’s continued problems keeping track of its parts have contributed to the Department of Defense’s overall inability to pass its own financial audits, the GAO said. That likely won’t change until the F-35 program addresses its parts tracking problems, the report said.
The GAO report recommends the Pentagon set up procedures to keep track of reports of lost F-35 parts, procedures and training for property officers to carry out their responsibilities, and spell out details on how the F-35’s accountable property officers must work, including how many are needed, where they should be, and how long it should take to do their jobs. GAO said in the report that the department is also taking steps to include F-35 parts on its financial statements, including setting up procedures to determine the value of lost parts where the cost information is missing.
In a statement, a F-35 Joint Program Office spokesperson noted that the office concurred with the GAO recommendations.
Yet it’s not just a question of the program office. Lockheed Martin, the primary manufacturer of the jet, and Pratt & Whitney, which makes the F-35’s engines, have sprawling supply chains, and their property management systems don’t plug in directly to the government’s enterprise logistics management system
As a result, the JPO has to upload data to its logistics system from several other equipment tracking sources. And because one of those sources is updated quarterly, some data on spares can be more than three months old and the JPO can’t see in real time when a part is moved or used.
The JPO’s physical inventorying of F-35 parts, as of fiscal 2025, were also unreliable. Since fiscal 2020, GAO said the JPO spent at least $17 million tallying parts in person at both contractor- and government-managed facilities. But because the records used aren’t reliable, some parts in transit aren’t counted, and the military and the program’s prime contractors don’t know where sub-subcontractors are holding some parts, those inventories have fallen short.
“To enhance accountability and mitigate the loss of F-35 parts, the department is implementing targeted actions to monitor and analyze loss trends. The JPO is actively developing program-specific procedures and tailored training for Accountable Property Officers, alongside a detailed plan to define and structure the APO program,” a spokesperson said. “The JPO is modernizing its property management infrastructure by establishing direct, real-time data interfaces between government and prime contractor systems. This integration directly addresses previous system gaps to ensure seamless accountability of F-35 spare parts.”
The issue of missing F-35 parts made headlines in September, when reports emerged that a package of sensitive parts heading from Australia to the United States to be repaired was diverted to Hong Kong and went missing earlier this year. POLITICO reported the shipment included a canopy that included sensitive stealth technology.