Somewhere in a warehouse, a repair shop or a shipping container, there is an F-35 part that the Pentagon owns, paid for and cannot find. Actually, there are a lot of them. And according to the US Government Accountability Office, the people in charge still do not have the records to say how many.

On Monday 9 November 2026, GAO published report GAO-27-108713, titled “F-35 Program: DOD Needs to Strengthen Oversight of Tens of Billions of Dollars in Parts.” Its headline finding is blunt: the F-35 Lightning II program holds roughly 26 million spare parts worth about $31 billion, spread across more than 700 contractor- and government-managed facilities worldwide, and the Department of Defense does not keep complete records of them.

Worse, the more than 1 million parts that went missing in GAO’s last look are still unaccounted for.

A $31 billion pool with patchy paperwork

The F-35 runs on a shared global spares pool. The US Air Force, the Navy, Marine Corps aviation and the foreign partners and customers all draw engines, tires, bolts and support equipment from the same stock. In theory that saves money. In practice, GAO says, it only works if somebody knows what is on the shelf.

The F-35 Joint Program Office (JPO) tracks those parts in a system called the Enterprise Logistics Management System. GAO found its records “inaccurate and incomplete” and not updated in real time. As of March 2026, about 17,000 parts in maintenance or repair, worth about $1.3 billion, had never been entered at all. Defense officials told the auditors the true figure could be as high as $2.5 billion.

The data that does arrive is not great either. Only 29 percent of the part records in a December 2025 contractor submission carried serial numbers, and only 43 percent had National Stock Numbers. Some components were listed as costing a cent or less, which GAO flagged as a likely data error rather than the bargain of the century.

Counting parts, expensively

Part of the problem is plumbing. Lockheed Martin and Pratt & Whitney run their own property systems, which do not feed directly into the government’s. So the JPO relies on periodic contractor uploads, and because the spares-pool data arrives quarterly, some records can be more than three months out of date.

Physical stock-takes have not closed the gap. Since fiscal 2020 the JPO has spent at least $17 million on inventories, about $12 million in 2019 and $5.5 million in 2025, according to the report. GAO found the fiscal 2025 count still did not fully verify that parts existed or that every part was counted. The Defense Contract Audit Agency is now working on a first full inventory, with a target completion date of March 2027.

The million parts nobody found

This is not GAO’s first visit. In May 2023 it reported that one prime contractor had lost more than 1 million F-35 parts worth over $85 million between May 2018 and October 2022. The new report says that as of March 2026, the JPO still did not know the status of those lost parts.

In June 2025 the Defense Contract Management Agency allowed the contractor to submit all its outstanding losses in one batch. By March 2026 it had reported about $28 million in losses dating from 2012 to 2025, and DCMA had so far found it financially liable for about $6 million. Because the JPO kept no record of outstanding losses, GAO says, it cannot tell whether that $28 million includes any of the parts from the 2023 review.

Why does it matter beyond the accountants? GAO links the problem directly to readiness. The Pentagon is pursuing what it calls the Global Support Solution Reset, an extra investment of about $13.7 billion that includes bringing F-35 parts supply up to required levels. Without reliable records, the auditors warn, the department may not know which parts it needs, in what quantities, or be able to account for the new ones it buys.

The Pentagon says it agrees

GAO made four recommendations, centred on procedures for monitoring lost parts and on proper procedures and training for the accountable property officers responsible for government-owned F-35 property. DOD concurred with all four.

The timing is awkward. In September, the program was already in the headlines after F-35 parts shipped from Australia to the United States for repair ended up in Hong Kong, a story Afterburner followed in F-35 Parts Diverted to Hong Kong: Australia Confirms the Shipment. Breaking Defense notes that GAO did not link that incident to the inventory problems in the new report.

CBS News reports in September 2026 on the F-35 parts shipped from Australia that were diverted to Hong Kong, the incident that put F-35 parts tracking in the spotlight.

The F-35 is the most expensive weapon program in history, with lifetime costs GAO puts at more than $1.9 trillion. The jet can fuse sensor data from across a battlefield. Its spares system, on GAO’s reading, still struggles to say what is in its own warehouses.

Sources: US Government Accountability Office (GAO-27-108713), Air & Space Forces Magazine, Breaking Defense