The Pentagon still cannot say with confidence where all of its F-35 spare parts are, and that gap now reaches into the billions of dollars. A new Government Accountability Office audit, reported by Breaking Defense, found that as of March 2026 more than 17,000 F-35 parts, worth an estimated $1.3 billion, were missing from the program’s inventory system. GAO officials put the possible value as high as $2.5 billion once missing cost information and other acquisition expenses are counted.
The finding lands on a joint pool of roughly 26 million spare parts valued at about $31 billion, spread across more than 700 contractor- and government-managed facilities worldwide. The department relies largely on its two prime contractors, Lockheed Martin for the airframe and Pratt & Whitney for the engine, for data on what exists and where.
“Without accurate data in its [accountable property system of record] and properly executed inventory procedures for F-35 parts, DOD management will not have the information it needs to support warfighter readiness and reliable financial reporting,” the GAO said.
Why ELMS Cannot See Lockheed and Pratt & Whitney Inventories
The Pentagon manages the fighter’s sprawling inventory through the Enterprise Logistics Management System, or ELMS. ELMS can capture real-time inventory changes, but it does not interface with the property management systems Lockheed Martin and Pratt & Whitney run. GAO first flagged that gap in 2022, and it persisted as of August 2026, Breaking Defense reported.
“For instance, records of F-35 parts in the F-35 program’s accountable property system of record remain unreliable, since they do not reflect real-time changes and are inaccurate and incomplete,” the GAO report states, according to Defense News.
Instead of a live feed, the F-35 Joint Program Office (JPO) depends on periodic contractor data submissions. For the joint spares pool those arrive quarterly, which means “joint spares pool data in ELMS may be more than 3 months old,” according to the report. Prime contractors also are not always aware of inventories their subcontractors hold, which leaves the physical location of some parts unclear.
Asif Khan, director of GAO’s financial management and assurance team, described the practical result to Defense News: “DoD does not have its own complete records of F-35 parts, and, as a result, does not know when a part is lost unless staff at the contractor-managed or government-managed facility identifies and reports the loss.”
One-Cent Parts and Missing Serial Numbers in the December 2025 Data
The JPO also lacks procedures to validate contractor data before it enters ELMS, and the quality problems show up in the submissions themselves. A December 2025 submission carried serial numbers for only 29 percent of parts records and National Stock Numbers for 43 percent, Breaking Defense reported.
Cost fields had their own problems. “Almost 6 percent of records of F-35 parts, also from the December 2025 CDRL, showed an acquisition cost of $0.01 or less, also indicating a possible data quality error,” the GAO noted.
Physical counts have not closed the gap. Since fiscal 2020 the JPO has spent at least $17 million conducting inventories, but GAO found its most recent effort did not fully verify that parts were physically in place or that records accounted for all of them. The audit’s bottom line was blunt: “Neither records of F-35 parts in ELMS nor F-35 JPO’s inventory results are reliable for the purpose of asset accountability or financial reporting,” the report states.
That unreliability makes even a loss estimate impossible. “Because the F-35 JPO has not established and implemented effective procedures for monitoring losses, we are unable to provide an aggregate estimate of how many of the 26 million parts are lost,” Khan told Defense News.
What Happened to the $85 Million in Parts GAO Flagged in 2023?
The new audit revisits an earlier finding. In 2023, GAO reported that a prime contractor had lost more than 1 million F-35 parts worth over $85 million between May 2018 and October 2022. As of March 2026, the JPO still did not know the status of those items.
By March 2026, the contractor had submitted about $28 million in loss reports covering missing parts between 2012 and 2025, according to Breaking Defense. The Defense Contract Management Agency determined the contractor should be financially liable for about $6 million. But the JPO could not determine whether those reports included any of the losses GAO identified earlier, because it had not kept records of outstanding cases.
How Parts Tracking Threatens the $13.7 Billion Sustainment Reset
GAO warned that the accounting failures reach beyond bookkeeping. Without accurate inventory records, the department may struggle to determine which parts it needs and in what quantities. That could complicate the Pentagon’s $13.7 billion Global Support Solution Reset strategy, which calls for more investment to improve F-35 performance, including spare parts availability. The watchdog cautioned that DoD may be unable to identify its needs or account for additional parts bought under the strategy.
Khan said F-35 customers have asked for greater transparency into the supply chain so they can allocate resources. “For several years, we’ve been reporting that DoD cannot ensure that the prime contractor is providing sufficient readiness at a reasonable cost without an understanding of the parts it owns and how the prime contractor manages those parts,” he said.
GAO made four recommendations, including procedures for monitoring reported losses with trend analyses to mitigate future losses, and clearer procedures, training and responsibilities for accountable property officers who track government-owned property. The Pentagon agreed with all four and said it was taking corrective action. The Defense Contract Audit Agency is also working with the JPO on a full inventory of F-35 parts, targeted for completion in March 2027.
A JPO spokesperson told Breaking Defense the office is “actively working” on the findings. “The JPO is modernizing its property management infrastructure by establishing direct, real-time data interfaces between government and prime contractor systems,” the spokesperson said. Lockheed Martin deferred questions on the report to the JPO.
What It Means for Contractors
For Lockheed Martin, Pratt & Whitney and the program’s thousands of suppliers, the direction is clear: the government wants direct, near-real-time visibility into property it owns. The JPO’s planned interfaces between government and prime contractor systems are meant to close the gap left by quarterly data submissions, and data quality in those feeds is likely to face closer scrutiny. Records missing serial numbers, National Stock Numbers or credible acquisition costs are exactly what GAO singled out.
Loss reporting is the second pressure point. The DCMA liability finding on the earlier losses shows that reported losses can turn into financial exposure for a contractor, and new JPO loss-monitoring procedures with trend analysis should make patterns easier to spot. Subcontractors that hold government-owned F-35 inventory could see primes push for faster, more complete reporting, especially ahead of the DCAA-supported full inventory due in March 2027.
