F-35 Sustainment: Actions Needed to Ensure Updated Strategy Improves Persistent Readiness Challenges

The F-35 Joint Strike Fighter is the most expensive weapons program in United States history, with total lifecycle costs projected to exceed one trillion dollars across the planned fleet of approximately 2,456 aircraft. The program spans three variants: the F-35A (Air Force, conventional), the F-35B (Marine Corps, STOVL), and the F-35C (Navy/Marines, carrier). Lockheed Martin is the prime contractor; Pratt and Whitney supplies the F135 engine. As of 2026, approximately 900 F-35s are operational across the three U.S. services, with allies flying additional aircraft under the original international consortium arrangements. For more than fifteen years, the program has struggled to meet DOD's mission capable rate targets. Contractor incentive payments totaling hundreds of millions of dollars have not produced measurable improvements in readiness. Depot capacity constraints, spare parts shortfalls, and unclear organizational responsibilities have compounded the challenge as the fleet grows and ages simultaneously.

This Nimble Ultra documentary edition presents verbatim GAO-26-108113, F-35 Sustainment: Actions Needed to Ensure Updated Strategy Improves Persistent Readiness Challenges, issued by the United States Government Accountability Office on June 11, 2026. The review was mandated by the National Defense Authorization Act for Fiscal Year 2025, which directed GAO to assess the status and implementation of DOD's F-35 sustainment strategy. The report evaluates DOD's 2025 Comprehensive Strategy for F-35 Readiness, a thirteen-point-seven billion dollar initiative to resolve the program's persistent readiness shortfalls through 2030. GAO finds that the strategy faces significant implementation risks: industry capacity constraints that have not yet been resolved, organizational roles and responsibilities within the F-35 sustainment enterprise that remain unclear, incentive structures whose payments have not driven the desired readiness results, and the absence of measurable implementation milestones against which Congress and the public can track progress. GAO issues four recommendations directed at the Secretary of Defense and the F-35 Joint Program Office. DOD partially concurred, stating that some elements are already being addressed through existing initiatives; GAO's evaluation of those comments, concluding they did not fully address the substance of the recommendations, is included in the appendix of the source document and reproduced in facsimile in this edition.

The Government Accountability Office is an independent, nonpartisan agency of Congress that provides objective, reliable information to help the government work better. GAO reports carry no enforcement authority but carry substantial moral weight: agencies respond formally to findings, and GAO publicly tracks implementation. This report is a work of the United States Government, public domain under 17 U.S.C. Section 105, and is reproduced here in facsimile without alteration. The editorial apparatus of this Nimble Ultra edition includes a Publisher's Note on GAO's role as congressional watchdog; a Document Guide covering report number, mandate, findings, and structure; and a Caveats and Counterpoints section gathering the principal uncertainties and contested perspectives - DOD's partial concurrence, Lockheed Martin's public positions, disputes over the mission capable rate metric, timing critiques of the strategy assessment, and the complexity of unit cost comparisons. The document is a reference tool, not an argument; Nimble Ultra takes no position on the F-35 program, its contractors, or any officials. ISBN: 979-8-25950-638-1 (Paperback), 979-8-25950-639-8 (Hardcover). EU AI Act Article 50 Disclosure: portions of the apparatus were generated with AI assistance; the primary source is verbatim.