The claim is everywhere — on defense forums, in congressional testimony, and in newspaper headlines: the Lockheed Martin F-35 costs 45% more to maintain than the F-16 it was designed to replace. But is that number accurate, and where does it actually come from? The question matters enormously, not just for the United States Air Force‘s budget, but for every allied nation that has committed to the Lockheed Martin stealth fighter as the backbone of its tactical aviation fleet. In a period of tightening defense budgets and rising geopolitical pressure, the true cost of keeping fifth-generation aircraft airworthy is a subject that demands precise answers rather than convenient soundbites.

The F-35 Lightning II was conceived as an affordable, multirole replacement for a range of legacy platforms, including the F-16 Fighting Falcon — one of the most cost-effective fighters in aviation history. Yet almost from the moment the program entered service, concerns about spiraling sustainment costs have dogged the Joint Strike Fighter. This article will unpack the key figures from government watchdogs, independent analysts, and the Pentagon itself, explain where the 45% figure originates, and provide the context needed to judge whether it is fair, misleading, or somewhere in between.

The Short Answer Is Yes — But With Important Caveats

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The short answer is: yes, the 45% figure is mathematically achievable, but only under a very specific set of comparisons and definitions. According to data compiled by the Congressional Budget Office (CBO), the F-35A’s total operating and support (O&S) cost currently sits at approximately $34,000–$36,000 per flight hour. When set against fully-loaded F-16C/D figures (those that include aging-fleet overhead costs of around $25,000–$27,000 per flight hour), the differential works out to roughly 30–45%, depending on which data points are used. That band of outcomes is precisely why the debate persists: advocates for the F-35 program can point to the lower end of the range, while critics reach for the upper end.

It is also worth noting that the 45% figure may have a second, equally plausible origin that has nothing to do with a head-to-head comparison with the F-16 at all. The F-35 program’s total projected sustainment cost grew from approximately $1.1 trillion in 2018 to roughly $1.58 trillion by 2023 — a rise of about 44%, eerily close to the frequently cited figure. Economy Insights has noted this parallel, suggesting the number may have migrated from a description of total program cost growth into a shorthand comparison with the F-16 , blurring two very different measurements in public discourse.

Historically, the F-16 earned its reputation as a workhorse partly because of its relatively low operating costs. When introduced in the late 1970s, it was celebrated as an affordable lightweight fighter, and decades of production refinement kept its sustainment costs competitive. The F-35, by contrast, carries the burden of stealth coatings that require careful maintenance, a sensor-fused avionics suite of extraordinary complexity, and a supply chain that, as of 2025, still relies heavily on the prime contractor for depot-level work, a structural cost driver that the legacy fleet never faced at the same scale.

What Factors Drive The F-35’s Higher Costs?

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Several interconnected factors push the F-35’s per-flight-hour costs well above those of the F-16. Understanding them is essential to assessing whether the gap will close over time or whether it is, in part, a permanent feature of what the aircraft is designed to do. The Government Accountability Office (GAO) has repeatedly identified three primary cost drivers:

• The contractor-led sustainment model
• Low aircraft availability rates that spread fixed costs across fewer flying hours
• The technical complexity of maintaining low-observable (stealth) surfaces.

The maintenance labor gap is especially striking. According to figures cited by Air & Space Forces Magazine, the F-35 requires roughly 160% more maintenance labor hours per flight hour than the F-16, a figure that dwarfs the 45% headline number and reflects the sheer density of systems that technicians must inspect, calibrate, and repair after every mission. The stealth coating alone requires specialized environmental facilities and trained personnel that simply did not exist in the legacy fleet’s maintenance system.

Low mission-capable rates compound the cost problem in a way that the raw per-flight-hour figure does not fully capture. When an aircraft is available to fly only 55% of the time, as recent GAO data suggests for the F-35 fleet, fixed costs such as personnel, facilities, and contract support are spread across fewer flying hours, automatically inflating the per-hour figure. The F-16, with decades of maturation, typically posts mission-capable rates in the 70–75% range, meaning its fixed costs are distributed more efficiently. Defense News reported that the GAO explicitly blamed the contractor-led Performance Based Logistics (PBL) model for slow turnaround times and inadequate spare parts availability, a structural issue rather than a simple engineering teething problem.

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What Do Government Watchdogs And Defense Officials Say?

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The most authoritative assessments of F-35 sustainment costs come not from advocacy groups or think tanks, but from the GAO and the Pentagon’s own Office of the Director of Operational Test and Evaluation (DOT&E). Year after year, those reports have told a consistent story: costs are rising, availability is falling, and the program has yet to produce a credible, funded plan to reverse either trend.

The GAO’s most recent major F-35 sustainment report found that costs have continued to increase while planned use and availability have simultaneously decreased, which is a troubling combination for a program that already faces scrutiny over value for money.

Defense One summarized the GAO’s position bluntly, noting that the F-35 program is costing more and delivering less operational capacity than originally projected. The F-35 Joint Program Office has pushed back on this characterization, arguing, as reported by Air & Space Forces Magazine, that costs are on a downward trajectory as production volumes increase and the contractor-led logistics system matures. The program office points to block upgrades and Technology Refresh 3 (TR-3) as investments that will ultimately reduce the cost-per-effect, even if the near-term cost-per-flight-hour remains elevated.

Military.com reported that the GAO has called on the F-35 program to develop a concrete, funded plan to cut billions from its long-term sustainment bill — something that, as of the most recent reporting cycle, remains partially unfulfilled. The implications extend well beyond the US Air Force. Nations including the UK, Australia, Italy, the Netherlands, and Japan have all purchased or ordered F-35s, meaning any structural cost problem in the sustainment model is an international issue. For smaller air forces operating the aircraft in limited numbers, the fixed overhead costs per flying hour can be even more punishing than for the US, which benefits from economies of scale across a fleet of over 600 aircraft.

How Does The F-35’s Cost Compare To Other Fighter Options?

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To assess whether the F-35’s sustainment cost is truly extraordinary, it helps to place it in the context of the broader fighter market. The F-35A does not compete in a vacuum, as its buyers are making decisions that implicitly or explicitly involve alternatives like the Boeing F-15EX, the Eurofighter Typhoon, the Dassault Rafale, and, for some nations, upgraded F-16 Block 70/72 aircraft. The F-35A’s per-flight-hour figure sits at the upper end of the Western tactical fighter range but is not entirely without precedent among complex, sensor-heavy platforms.

The F-15EX, for example, carries its own substantial per-flight-hour costs with estimates in the $28,000–$32,000 range for total O&S, owing to its large twin engines and sophisticated avionics. The Eurofighter Typhoon’s operating costs vary significantly by operator nation, but European parliamentary inquiries have cited figures in a broadly similar range to the F-35A. The critical difference is that those aircraft lack the F-35’s stealth capability, which is the primary rationale for accepting its higher sustainment burden. Comparing costs without accounting for capability is, as the F-35 program office frequently argues, an incomplete analysis.

Where the F-35 does stand out unfavorably is when compared specifically to the F-16 on a pure cost-per-flight-hour basis, which is the comparison that drives the headlines. As we previously covered, the gap between the two aircraft, in total O&S terms, is closer to 55–65% than to 45%, a more honest figure that uses the most widely cited government data and avoids cherry-picking the narrowest possible cost definition to minimize the differential. The 45% figure represents a best-case scenario for the F-35 rather than a central estimate.

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Are There Exceptions, Risks, Or Reasons The Gap Could Close?

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The cost story for the F-35 is not entirely static, and there are legitimate reasons to believe the gap with the F-16 could narrow, though probably not close entirely. The F-35 program is still relatively young in sustainment terms, and historical patterns with complex military aircraft suggest that costs tend to peak in the early years of fleet maturity and decline as spare parts inventories build up, depot repair lines become established, and maintenance technicians accumulate experience. The F-16 itself was not immune to high early sustainment costs before decades of refinement brought them down to their current levels.

The ongoing transition toward military-owned depot maintenance, rather than exclusive reliance on Lockheed Martin’s contractor support, could also reduce per-flight-hour costs meaningfully. The US Air Force has been pushing to bring more F-35 maintenance in-house, and early results from expanding organic capability have been moderately encouraging. Engine modernization decisions made specifically to upgrade the Pratt & Whitney F135 engine or pursue a competitive replacement will also have a significant bearing on future sustainment costs, as the GAO noted in its Joint Strike Fighter engine modernization report.

Readers should be cautious, however, about projections that assume large future cost reductions without a funded, detailed plan behind them. The GAO has specifically flagged the absence of such a plan as a major program risk. Until the F-35 Joint Program Office produces and executes a credible sustainment cost-reduction roadmap, the gap with the F-16 should be treated as structural rather than temporary. Anyone citing the 45% figure should also ask which cost definition it uses, whether it includes indirect costs, and whether it reflects actual recent spending data or older projections made when the program was more optimistic about its cost trajectory.

The 45% Claim Is Real—But Often Misleading

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The 45% figure is not a myth, but it is not the full story either. It is, at best, the low end of a range of defensible comparisons between F-35A and F-16C/D sustainment costs. And it may, in fact, be a mislabeled statistic that originated from the F-35 program’s own internal cost growth between 2018 and 2023 rather than any head-to-head fleet comparison. The more comprehensive and honest summary, drawn from the most widely cited CBO and GAO data, is that the F-35 costs roughly 55–65% more per flight hour in total operating and support terms than the F-16C/D, and approximately 160% more in maintenance labor hours specifically. Those are the figures that defense planners, allied governments, and taxpayers should be working from.

For the air forces that have already committed to the F-35, the question is how to make this aircraft as affordable as possible in service. That means accelerating the transition to organic depot maintenance, pressing Lockheed Martin on spare parts availability and pricing, and monitoring the engine modernization decision closely — since propulsion is one of the largest single drivers of sustainment cost for any tactical aircraft. Partner nations with smaller fleets should also explore deeper multinational sustainment cooperation to spread fixed infrastructure costs across a larger number of flying hours.

The F-35’s cost trajectory will be one of the defining data points for the next generation of fighter procurement decisions worldwide. If the program can demonstrate a credible, sustained decline in per-flight-hour costs over the next five to ten years, it will vindicate the arguments of those who say the aircraft’s capabilities justify its price. If costs continue to rise as they have, almost without interruption, since the program entered service, it will fuel pressure for genuine competition in tactical aviation and accelerate interest in lower-cost complement platforms like the F-16 Block 70, the T-7A, and future loyal wingman concepts.