By Outrider Editorial Team · Updated August 20, 2026
Official definition
This U.S. industry comprises establishments primarily engaged in one or more of the following: (1) manufacturing aircraft engines and engine parts; (2) developing and making prototypes of aircraft engines and engine parts; (3) aircraft propulsion system conversion (i.e., major modifications to systems); and (4) aircraft propulsion systems overhaul and rebuilding (i.e., periodic restoration of aircraft propulsion system to original design specifications).
FY2025 obligations
$12.0B
Contract actions
8,518
IDVs
615
Top buying agencies
- Department of Defense$12.0B
- Department of Homeland Security$45.6M
- Department of Justice$2.1M
- Department of State$2.0M
- Department of Transportation$1.9M
FY2025 federal contract obligations, USAspending.gov
NAICS 336412 obligated $12 billion in FY2025 across 8,518 contract actions. DoD is $11.97 billion, or 99.6 percent, making this the most defense-concentrated aerospace code after complete aircraft. DHS at $46 million covers Coast Guard powerplants; DOJ, State, and DOT together obligated under $7 million. If you are building a federal pipeline on this code, you are building a DoD pipeline.
What belongs here
Aircraft engines and engine parts, engine prototypes, propulsion system conversion, and propulsion overhaul and rebuilding. That last item is the important asymmetry: engine MRO stays inside the manufacturing code, while airframe maintenance short of a full rebuild does not.
- Airframes, conversions, and complete aircraft rebuild are 336411.
- Non-engine parts and auxiliary equipment are 336413.
- Internal combustion engines that are not automotive or aircraft are 333618.
Competing in this code
615 IDVs against 8,518 actions puts this between the closed platform codes and the open spares codes. The middle tier is where engine accessory and component shops live: fuel controls, gearboxes, bearings, blades, and the repair sources qualified against them. Qualification is the barrier, not size. The 1,500-employee standard admits nearly every shop that could realistically do the work, so the differentiator on award is source approval and repair capability certification held against the specific engine family.
Frequently Asked
NAICS 336412 questions, answered.
What is the SBA size standard for NAICS 336412?
SBA sets it at 1,500 employees, counted as a 24-month average headcount across your company and every affiliate, not revenue. At or under that number you are small on NAICS 336412 solicitations and eligible for the set-asides in this code.
Which agencies buy aircraft engines and engine parts under NAICS 336412?
FY2025 obligations: DoD ($12 billion), DHS ($46 million), DOJ ($2 million), State ($2 million), DOT ($2 million). At 99.6 percent DoD, this is the most defense-concentrated engine market in the federal government.
Is engine overhaul classified under NAICS 336412?
Yes. The Census definition explicitly includes aircraft propulsion system conversion and propulsion systems overhaul and rebuilding. That differs from the airframe code, where only full restoration to original design specification counts as manufacturing. Engine MRO shops belong in 336412.
What separates NAICS 336412 from 333618?
Application. 336412 is aircraft propulsion. 333618 covers internal combustion engines that are neither automotive gasoline nor aircraft, which is where marine diesels, generator prime movers, and industrial engines land. A shop rebuilding both should register both, because the buyers do not cross-search.
Register Under NAICS 336412
Classify your business correctly to maximize visibility to federal buyers and access small business set-asides.
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