Pentagon Can't Track More Than 17,000 F-35 Parts Worth Up to $2.5 Billion, GAO Finds

The Pentagon cannot account for more than 17,000 F-35 parts in the program's own inventory system, according to a new report from the US Government Accountability Office (GAO). The missing parts are valued at about $1.3 billion. Officials told GAO the figure could be as high as $2.5 billion once missing cost data and other acquisition expenses are counted.

The snapshot dates from March 2026, when GAO carried out its research. The Pentagon agreed with all four of the watchdog's recommendations and says it is taking corrective action.

What GAO found in the F-35 inventory records. Militrax graphic.

Why the parts go missing on paper

The F-35 supply chain is enormous. GAO counts more than 1,900 US suppliers and 2,100 foreign ones, with about 26 million parts spread across more than 700 contractor and government sites worldwide. The jet flies in three main variants for the US Air Force, Navy and Marine Corps, plus versions for 19 international customers.

The Defense Department tracks this inventory in a system called the Enterprise Logistics Management System, or ELMS. GAO says ELMS still cannot connect to the property systems run by Lockheed Martin, the prime contractor, and Pratt & Whitney, which builds the engine. GAO first flagged that gap in 2022, and it was still there in August 2026.

Instead, the F-35 Joint Program Office relies on periodic data sent by the contractors. Some of it arrives quarterly, so records can be more than three months old. GAO found the office has no procedure to check that data before it goes into ELMS.

The quality problems are visible in the numbers. In one contractor submission from December 2025, only 29% of parts records carried a serial number and 43% a National Stock Number. Some components were listed at a cost of one cent or less, which GAO said pointed to data errors.

Losses, inventories and a $13.7 billion plan

This is not the first warning. In 2023 GAO reported that a prime contractor had lost more than 1 million F-35 parts worth over $85 million between 2018 and 2022. By March 2026 that contractor had filed about $28 million in loss reports covering 2012 to 2025, and the Defense Contract Management Agency found it should be liable for about $6 million.

Since fiscal 2020 the program office has spent at least $17 million on inventories. GAO says the latest one did not fully check that parts were physically where the records said, or that the records covered every part.

The timing matters because the Pentagon plans to spend more on spares. GAO warned that a $13.7 billion sustainment plan, which includes buying more spare parts, could be undermined if the department cannot see what it already owns or account for what it adds.

An F-35A at Luke Air Force Base, Arizona. File photo, U.S. Air Force (public domain).

What happens next

The program office says it is building direct, real-time data links between government and contractor systems, and adding new procedures and training for officials who handle government-owned property. Lockheed Martin referred questions about the report to the program office.

A full inventory of F-35 parts, run with the Defense Contract Audit Agency, is targeted for completion in March 2027.