
Program · United States · U.S. Air Force
KC-135 Stratotanker
Aerial-refueling aircraft supporting U.S. and allied aircraft.
Cost to the Government
| Measure | Amount | Source |
|---|---|---|
| Program totals · 1 | ||
| R&D program totalA separately identified lifetime development total has not been verified. This is not a zero-cost estimate. | Not established | — |
| Unit costs · 1 | ||
| Published acquisition / aircraftHistorical fact-sheet figure; not a current replacement quote. | $39.6MConstant FY1998 $ | KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026 |
| Quantities · 2 | ||
| Published U.S. fleet snapshotSource inventory snapshot; subsequent retirements, transfers and losses are not inferred. | 396U.S. only | KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026 |
| Program quantityA comparable total acquisition quantity has not been verified. | Not established | — |
| Operating costs · 2 | ||
| Annual O&S / aircraftHistorical average for the source study population; not a marginal mission cost. | $10.65M / yrConstant FY2018 $ | Weapon System Sustainment: GAO-21-101SP, FY2011–2018 operating costs GAO · figure FY2018 |
| Reimbursement / flight hourPublished billing rate for use by another DoD component. It is not the fully burdened cost of ownership. | $20,959 / hrNominal $; Other DoD Component | FY2026 aircraft hourly reimbursement rates, Other DoD Component column DoD Comptroller · figure FY2026 |
Program totals · 1
- R&D program totalA separately identified lifetime development total has not been verified. This is not a zero-cost estimate.Source not recordedNot established
Unit costs · 1
- Published acquisition / aircraftHistorical fact-sheet figure; not a current replacement quote.KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026$39.6MConstant FY1998 $
Quantities · 2
- Published U.S. fleet snapshotSource inventory snapshot; subsequent retirements, transfers and losses are not inferred.KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026396U.S. only
- Program quantityA comparable total acquisition quantity has not been verified.Source not recordedNot established
Operating costs · 2
- Annual O&S / aircraftHistorical average for the source study population; not a marginal mission cost.Weapon System Sustainment: GAO-21-101SP, FY2011–2018 operating costs GAO · figure FY2018$10.65M / yrConstant FY2018 $
- Reimbursement / flight hourPublished billing rate for use by another DoD component. It is not the fully burdened cost of ownership.FY2026 aircraft hourly reimbursement rates, Other DoD Component column DoD Comptroller · figure FY2026$20,959 / hrNominal $; Other DoD Component
Earlier observations · 3
Superseded estimates and prices, each in its original scope and dollar basis.
| Measure | Amount | Source |
|---|---|---|
| Unit costs · 1 | ||
| Published acquisition / aircraftHistorical fact-sheet figure; not a current replacement quote. | $39.6MConstant FY1998 $ | KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026 |
| Operating costs · 2 | ||
| Annual O&S / aircraftHistorical average for the source study population; not a marginal mission cost. | $10.65M / yrConstant FY2018 $ | Weapon System Sustainment: GAO-21-101SP, FY2011–2018 operating costs GAO · figure FY2018 |
| Reimbursement / flight hourPublished billing rate for use by another DoD component. It is not the fully burdened cost of ownership. | $20,959 / hrNominal $; Other DoD Component | FY2026 aircraft hourly reimbursement rates, Other DoD Component column DoD Comptroller · figure FY2026 |
Unit costs · 1
- Published acquisition / aircraftHistorical fact-sheet figure; not a current replacement quote.KC-135 fact sheet U.S. Air Force · figure Undated fact sheet; reviewed Oct 9, 2026$39.6MConstant FY1998 $
Operating costs · 2
- Annual O&S / aircraftHistorical average for the source study population; not a marginal mission cost.Weapon System Sustainment: GAO-21-101SP, FY2011–2018 operating costs GAO · figure FY2018$10.65M / yrConstant FY2018 $
- Reimbursement / flight hourPublished billing rate for use by another DoD component. It is not the fully burdened cost of ownership.FY2026 aircraft hourly reimbursement rates, Other DoD Component column DoD Comptroller · figure FY2026$20,959 / hrNominal $; Other DoD Component
Reading the cost figures
The fact-sheet acquisition figure uses the dollar basis shown above. GAO’s annual operating and support cost includes a broader ownership scope than the Comptroller reimbursement rate. These figures should not be combined into a single inflation-free trend.
Open research: Figures retain the date and scope of the original source. A historical count, cumulative delivery or procurement plan is not today’s mission-capable inventory. A separately identified lifetime development total has not been verified. This is not a zero-cost estimate.
What the government budgets and pays for this program, from budget justification books, appropriations, acquisition reports and contract announcements. Each figure states its dollar basis. What contractors were obligated is under Contracts.
