By Amara Osei

The Pentagon holds roughly 26 million F-35 parts worth an estimated $31 billion, but cannot reliably track them, according to a Government Accountability Office (GAO) review that found inventory gaps as of March 2026. The GAO said the control failure leaves the program without dependable information on where parts are located, what they are worth, how many exist and which ones it needs.

What did the watchdog find?

In its Monday report, the GAO said the US Department of Defense (DoD) still could not determine the status of more than 1 million F-35 parts worth over $85 million that it had flagged in 2023. Contractor-managed facilities had failed to maintain complete parts records, leaving the F-35 Joint Program Office (JPO), which oversees the program, unable to establish whether those losses had been resolved.

The JPO also could not determine whether more recently reported losses included any of the previously identified parts. The F-35 Lightning II Joint Strike Fighter is the most expensive weapon-system program in history. It has persistent spare-parts problems alongside rising acquisition and sustainment costs (the continuing expense of operating and maintaining the aircraft).

Why has inventory management failed?

The central problem sits with the Enterprise Logistics Management System (ELMS), which combines parts data from several sources. The GAO found ELMS unreliable because it lacks real-time updates, does not consistently reflect changes and statuses, and cannot connect directly to prime contractor (lead supplier) systems.

The Pentagon's official records also remain incomplete. As of March 2026, the JPO's official system still lacked entries for roughly 17,000 parts worth about $1.3 billion, although those parts were undergoing maintenance or repair. Officials told the GAO that the value could reach $2.5 billion once transportation and overhead were included.

The GAO warned: "The data are not reliable for asset accountability or financial reporting." It added: "Timely and accurate data on F-35 parts are also important to ensure that the F-35 program is positioned to meet the needs of the warfighter."

Where are the parts held?

The Pentagon's inventory sits across more than 700 government- and contractor-managed facilities. Government sites hold about 70% of parts, while contractors store the remaining 30%, a division that complicates asset accountability.

Since 2020, the JPO has spent at least $17 million on physical inventories at government and contractor sites. The GAO said those efforts had not adequately resolved the recordkeeping deficiencies.

The report set the condition for correction: "Until the interfaces with contractors' systems are established and effective validation procedures to ensure data quality are implemented, DoD will not have accurate information about where its F-35 parts are located, what their value is, and how many there are."

What is the DoD doing?

The DoD accepted the GAO recommendations. A JPO spokesperson said the department was implementing specific actions to monitor and analyze loss trends.

Accountable Property Officers (APOs) oversee government-property accountability. The spokesperson said: "The JPO is actively developing program-specific procedures and tailored training for Accountable Property Officers (APOs), alongside a detailed plan to define and structure the APO program."

How does this affect readiness?

The GAO regularly reviews the F-35 program and has linked spare-parts shortages and maintenance problems to lower aircraft availability. Earlier in 2026, it reported that the mission-capable rate (the share of time an aircraft is available to perform one mission) fell from 67% in fiscal year 2021 to 44% in fiscal year 2025.

The full mission-capable rate (the share of time an aircraft can perform all missions) dropped from 38% to 25% over the same period. The F-35 supports air-to-air combat, ground attack, surveillance and electronic warfare, and the US military operates three variants:

• F-35A: Built for conventional runways.
• F-35B: Able to take off from shorter runways and land vertically.
• F-35C: Designed for aircraft-carrier operations.

The DoD launched a $13.7 billion readiness plan in 2025 to improve aircraft availability by the end of the decade, although the investment could cost more than expected. The latest GAO report warned that unreliable inventory records could make it difficult to determine which parts the program needs and in what quantities.