Printed from https://fiscalreceipts.com/program/F03500/ — built September 26, 2026. Every figure is citation-backed; see the page online for per-number provenance.
F-35 Modifications
Budget figures
FY2026 award data is a partial year — USAspending reports awards on a rolling basis, and this corpus runs through 2026-09-04. why partial FY2026 data? →
Budget trajectory
| Fiscal year | Amount |
|---|---|
| FY24 | $329.4M |
| FY25 | $394.5M |
| FY26 | $380.3M |
All series figures: P-1 TOA · PB2026
Decade view
P-1/R-1 workbook TOA basis, shown compact in $B/$M (the workbook records USD thousands); each figure cites its own President's Budget edition
The vertical scale does not start at zero: the baseline sits just below this program’s smallest year, so a low point on this line is not a small amount. Read the shape for direction and the grid below for the figures.
● actuals (line) · ○ enacted · ◇ request — gaps are editions the program is absent from, never interpolated.
| Series | FY22 | FY23 | FY24 | FY25 | FY26 |
|---|---|---|---|---|---|
| Actuals | $247.9M | $333.1M | $329.4M | ||
| Enacted | – | $333.1M | $451.8M | $394.5M | |
| Request | – | – | $451.8M | $549.7M | $380.3M |
blank = series not published for this year; – = absent from that edition.
Asked vs spent: the PB2024 book requested $451.8M for FY2024; the PB2026 book reported $329.4M as actual total obligation authority — $122.4M below the request. 329.4 − 451.8 = -122.4 USD millions — the compact figures above are rounded for reading.
Program lineage
No predecessor/successor lineage was recorded for this program element — no FY-to-FY transfer into or out of this line was stated in the ingested J-books, and none was inferred from the program structure.
Description
Description — F-35 Modifications
The F-35 Joint Strike Fighter (JSF) Program will develop and deploy a family of highly common, affordable, next generation, stealthy, multi-role strike fighters that meet the needs of multiple services and countries. The United States Air Force F-35A Conventional Take Off and Landing (CTOL) line item funds modifications and retrofits to the F-35A aircraft and integrated air systems. The overall effort provides correction of deficiencies, near and long-term improvements to the fleet, focusing on documented deficiencies related to safety, maintainability, and aircraft systems. These modifications and selected component changes are accomplished by field and depot retrofit. Block upgrades provide more robust performance in navigation, weapons, avionics, survivability, maneuverability, maintainability, and mission deployment of the F-35A platform. This modification program will bring early production aircraft and integrated systems to a common fleet configuration as fielded capabilities evolve over the course of the F-35 program. In order to meet emerging deficiencies, the airframe and integrated systems must be modified as critical corrections/changes are identified. Funds will be used to manage, prepare, process, and incorporate changes to sustain and improve F-35A system operations. The Structural Life Limit Parts (SLLP) Program is the preponderance of the correction of deficiencies effort. The Structural Life Limit Parts Program Group 2 (SLLP2) will remove life limits below 4,000 hours. The Engineering Change Proposals (ECP) necessary to extend the life of the aircraft to 8,000 hours is known as SLLP3. In 2025, the Program will procure and install SLLP2 modifications while continuing to mature engineering for SLLP3 ECPs and progressing to material purchases in future years. Funding may be used to address Diminishing Manufacturing Sources (DMS) issues. DEVELOPMENT STATUS/MAJOR DEVELOPMENT MILESTONES Technology refresh (TR-3) kit procurements will continue in FY 2026 for F-35A aircraft. The F-35 Program will simultaneously be procuring 42Px Kit A and 42Px Kit B retrofits in order to deliver baseline Block 4 capabilities to fleet aircraft. Note: (1) United States Air Force (USAF) Initial Operational Capability (IOC) occurred on 2 August 2016 and the Full Rate Production (FRP) occurred on 12 March 2024.
Justification
Justification — F-35 Modifications
Basis for FY 2026 budget request is to continue to fund the F-35A Total Active Inventory of 541 aircraft. FY 2026 funding decreased as a result of a decrease in number of aircraft being procured in FY 2026.
Budget line items(workbook-cited)
P-1/R-1 workbook Total Obligation Authority basis (USD thousands) · PB2026.
Exhibit P-1
| Account | Org | Type | Amount |
|---|---|---|---|
| Aircraft Procurement, Air Force | F | FY24 Actuals | $329.4M |
| Aircraft Procurement, Air Force | F | FY25 Enacted | $394.5M |
| Aircraft Procurement, Air Force | F | FY26 Disc. Request | $380.3M |
| Aircraft Procurement, Air Force | F | FY26 Total | $380.3M |
Budget Details(R-2/P-40 facts)
J-book detail basis (R-2/P-40, USD millions) · PB2026 — a different accounting basis from the P-1/R-1 workbook TOA above; where the two disagree, the reconciliation strip under Budget figures shows both.
Wider than this screen — swipe the table sideways for the remaining fiscal-year columns.
| Project | All Prior Years | FY24 Actuals | FY25 Total | FY26 Base | FY26 Request |
|---|---|---|---|---|---|
| Program Element | $2.01B | $329.4M | $394.5M | $380.3M | $380.3M |
Follow the dollar
No follow-the-dollar view — this program's awards haven't been crosswalked at high confidence (flows cover 312 of 1,938 programs). why coverage is partial? →
Related awards
Award linkage is shown for 32 of 200 profiled companies — high- and medium-confidence USAspending matches, each row labeled; medium is the weaker evidence. why partial award coverage? →
Rows marked medium rest on evidence weaker than a program-level match, and of more than one kind. An account-based row, where the award drew from the same appropriation account as this program, is an association, not evidence that this program paid for the contract. Where the evidence is instead an FPDS acquisition-program tag or a subaward description, the program is established but which of its budget lines paid is not. An announcement link a recorded review did not leave standing is medium too. Only high rows rest on the contract naming this program with a recorded review upholding it and no recorded rejection or refutation applying.
Showing 25 of 118 award records (this program's published budget→award crosswalk links — see methodology)
| Recipient | PIID | Confidence |
|---|---|---|
| ALVAREZ LLC | N6833520F0409 | medium |
| BOOZ ALLEN HAMILTON INC | N0001920F0476 | medium |
| BOOZ ALLEN HAMILTON INC | N6833520F0672 | medium |
| CACI IDT, LLC | N0001921F0232 | medium |
| CDW GOVERNMENT LLC | N6833520F0271 | medium |
| DARK WOLF SOLUTIONS, LLC | FA701420F0040 | medium |
| DELL FEDERAL SYSTEMS L.P | N0001921F0872 | medium |
| DELL FEDERAL SYSTEMS L.P | N6833520F1150 | medium |
| DELL MARKETING L.P. | N0001921F0230 | medium |
| EXECUTIVE BUSINESS SERVICES, INC. | N0001921F0237 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0174 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0294 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0394 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0430 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0510 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833519F0592 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F0227 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F0676 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F0685 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F1619 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F1620 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833520F1621 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833521F0206 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833521F0208 | medium |
| FLATWATER SOLUTIONS COMPANY | N6833521F0209 | medium |
Contractor concentration
No concentration index is published for this line. This line's high-confidence links do not clear the floor for a published concentration index — at least 3 awards across 2 contractor families holding positive obligations, with positive net linked dollars. An index below that floor is a fact about the sample, not about the market. Whatever further links this line carries are medium-confidence, and what each medium evidence path does and does not establish is set out in the methodology. Both bases are in the downloadable warehouse.
Lobbying mentions
No Senate LDA lobbying filing in the tracked data mentions this program element by code or alias.
Oversight
GAO oversight of this program
GAO reports naming this program:
- F-35 Joint Strike Fighter: Program Continues to Encounter Production Issues and Modernization Delays (GAO-24-106909, May 16, 2024)
- F-35 Joint Strike Fighter: More Actions Needed to Explain Cost Growth and Support Engine Modernization Decision (GAO-23-106047, May 30, 2023)
- F-35 Joint Strike Fighter: Cost Growth and Schedule Delays Continue (GAO-22-105128, April 25, 2022)
GAO assessed the program, not this budget line. F-35 Modifications is one of the lines that funds it, and GAO’s work above says nothing about this line’s own figures. Which line each GAO item attaches to is a hand-ratified crosswalk — how it was checked.
Department-level designation (not specific to this program)
GAO lists 5 high-risk areas for DOD as a whole. That designation covers the department, not F-35 Modifications. GAO's program-level work on this line is above. See the DOD oversight record.
Program dossier
No research dossier for this program — dossiers cover 50 of 1,938 programs, the largest fully J-book-detailed lines by FY2026 requested dollars. why no dossier here? →
Primary sources
Open any budget figure for its exact receipt. Verified line items lead with the highlighted government PDF; original spreadsheets download with their budget edition and exhibit in the filename.
Budget totals · TOA sources
FY2026 Department of Defense Budget: Procurement Programs (P-1) · comptroller.war.gov
Exhibit P-1 · O878
Complete workbook · unchanged saved copy. Saves as PB2026_DoD_P-1_Procurement.xlsx.
FY2024 Department of Defense Budget: Procurement Programs (P-1) · comptroller.war.gov
Exhibit P-1 · O848
Complete workbook · unchanged saved copy. Saves as PB2024_DoD_P-1_Procurement.xlsx.
FY2025 Department of Defense Budget: Procurement Programs (P-1) · comptroller.war.gov
Exhibit P-1 · O894
Complete workbook · unchanged saved copy. Saves as PB2025_DoD_P-1_Procurement.xlsx.
Detailed budget justification
The related TOA spreadsheets above use a different accounting basis from R-2/P-40 detail. Their amounts are not assumed to match these detailed sources.
FY2026 Air Force Aircraft Procurement, Vol. I · www.saffm.hq.af.mil