The Pentagon cannot reliably track the roughly 26 million F-35 parts it owns at Defense Department installations and contractor facilities across the globe, according to a new Government Accountability Office analysis published Monday.
GAO analysts found that the Pentagon’s F-35 office cannot accurately track about $31 billion of the components it owns, cannot account for items reported missing, and has not sufficiently trained staff members to oversee the status of parts in the program, Stars and Stripes reported.
The F-35 Lightning II stealth fighter is the most expensive weapons program in U.S. history, expected to cost taxpayers nearly $2 trillion over its life cycle, according to GAO. The aircraft is built in three variants, flown by the Air Force, Navy and Marine Corps and by more than a dozen allied militaries.
A $31 Billion Gap in F-35 Parts Accounting
“DOD has long-standing and ongoing deficiencies related to the accountability and financial reporting of F-35 parts,” GAO analysts wrote, noting that the department’s inability to properly monitor the program has contributed significantly to the Pentagon’s failure to pass a financial audit.
The watchdog also warned that the inventory problems could affect F-35 warfighting capabilities. The program has long been plagued by delays, cost overruns and problems with parts management, according to GAO.
One of the central problems identified in the report is the joint program office’s inability to track in real time the components it owns but which sit at hundreds of contractor locations. GAO estimated that about 70% of DOD’s F-35 inventory was held at government facilities, with the remaining 30% at contractor-owned locations.
More Than 17,000 Components Missing From the Logistics Database
Pentagon officials themselves have contributed to the data reliability problems. GAO analysts found that officials had not entered some 17,000 F-35 components in various phases of maintenance and repair into the logistics database.
Breaking Defense, in coverage summarized by UA.News, reported that as of March 2026 the program’s accounting system lacked data on more than 17,000 F-35 Lightning II components with an estimated value of $1.3 billion. Taking into account missing cost information and other expenses tied to acquiring them, that figure could reach $2.5 billion.
GAO also found that some items were not tracked while in transit via commercial shippers and “may not be included in the inventory records.”
Contractor Data the Pentagon Cannot Verify
The report found that the F-35 office has not established reliable procedures for verifying data it receives from prime contractors, describing many of the submissions as “inaccurate and incomplete.”
In many cases, prime contractors do not know where components held by lower-level suppliers are located, “because the prime contractors do not have visibility of parts held beyond the subcontractor level, such as those held at sub-subcontractor facilities,” GAO found.
According to the Breaking Defense account, the Enterprise Logistics Management System can record inventory changes in real time but does not interact with the property management systems of Lockheed Martin and Pratt & Whitney. The program office instead receives contractor data periodically, and submissions for the shared parts pool are made quarterly, meaning some records may be more than three months out of date.
The quality of those submissions drew specific criticism. In the December 2025 submission, serial numbers were included in only 29% of records and national stock numbers in 43%. Some items were listed at a price of one cent or less, which auditors said may indicate data errors.
Pentagon officials said they are working to establish an interface that would give the F-35 office “a live connection” between its inventory software and that of prime contractors holding parts.
Minimal Progress Since 2019
The new report is the third GAO has published since 2019 examining the financial management of the F-35 Joint Strike Fighter program. It found that the Defense Department has “made minimal progress” in implementing GAO’s past recommendations.
For example, GAO reported, the Pentagon had not fully implemented “periodic physical inventories” of components housed at some 700 different locations, something the watchdog first recommended in 2022. The disconnect between the logistics system and contractor property systems was also first flagged in 2022 and, as of August 2026, had not been resolved.
Since fiscal year 2020, the program office has spent at least $17 million on inventories, but the most recent inspection did not fully confirm the physical presence of items or the consistency of records with actual inventory. In 2023, GAO reported that the prime contractor had lost more than one million F-35 components worth over $85 million between May 2018 and October 2022.
Four Recommendations the Pentagon Accepted
GAO recommended that the Defense Department build and implement new, specific procedures to monitor losses of components, develop new training for property managers, and study its property management program to determine precisely how many officials it needs to better monitor the program. Defense Department officials agreed with the recommendations, GAO reported.
Breaking Defense reported that the department agreed with all four recommendations, which call for stronger controls over reports of lost spare parts along with clearer procedures, training and assignment of responsibility for accounting for government property. The Defense Contract Audit Agency, working with the program office, is conducting a full inventory that is planned for completion in March 2027.
Auditors said that without accurate data in the property accounting system and proper inventory procedures, the department will lack the information it needs to maintain combat readiness and produce reliable financial reporting.
“Unless it takes steps to address the identified issues, DOD will continue to struggle with accountability of F-35 parts, which will affect warfighter readiness and DOD’s ability to report reliable information in its financial statements,” the report concluded.
