What NAICS code should a general contractor use?

Most commercial general contractors use 236220 (Commercial and Institutional Building Construction), which covers offices, schools, hospitals, retail, and other non-residential buildings. Residential GCs use the 236100 series, and heavy/civil primes use the 237 series. Your primary NAICS code should reflect the majority of your revenue.

What is the NAICS code for a construction company?

There is no single code — construction is NAICS Sector 23, split into three subsectors: 236 (building construction, used by general contractors), 237 (heavy and civil engineering, e.g., highways and utilities), and 238 (specialty trade contractors, used by subcontractors like electricians and plumbers). Pick the six-digit code that matches your main line of work.

What is the difference between NAICS 236, 237, and 238?

236 (Construction of Buildings) covers general contractors that build residential, commercial, and industrial structures. 237 (Heavy and Civil Engineering Construction) covers infrastructure primes — highways, bridges, utilities, and pipelines. 238 (Specialty Trade Contractors) covers subcontractors performing a single trade such as electrical, plumbing, concrete, or roofing.

What NAICS code is electrical, plumbing, or concrete work?

Electrical contractors use 238210, plumbing/HVAC/mechanical contractors use 238220, and poured-concrete foundation and structure contractors use 238110. Structural steel and rebar fall under 238120. Search your trade above to find the exact six-digit code.

How do NAICS codes relate to SAM.gov and small-business set-asides?

When you register in SAM.gov, you select the NAICS codes that describe your work. Federal set-aside programs — 8(a), HUBZone, SDVOSB, and WOSB — and small-business size standards are applied per NAICS code. Whether you qualify as a small business depends on the SBA size standard for the specific code you bid under.

What is the SBA small-business size standard for construction?

For most building and heavy/civil construction codes (NAICS 236 and 237), the SBA size standard is $45.0 million in average annual receipts; Other Heavy and Civil Engineering Construction (237990) is $37.0 million. For specialty trade contractors (NAICS 238), the standard is $19.0 million. If your five-year average receipts are below the threshold for your code, you qualify as a small business.

NAICS Code Lookup for Construction | Free Contractor Tool

The NAICS Code Lookup for Construction lets general contractors and subcontractors find the correct North American Industry Classification System code for their work. Construction is Sector 23, divided into 236 (building construction), 237 (heavy and civil engineering), and 238 (specialty trade contractors). NAICS codes determine SAM.gov registration, federal set-aside eligibility, and SBA small-business size standards.

Search Construction NAICS Codes

Search by trade, keyword, or six-digit code (e.g., “electrical”, “paving”, “236220”).

Enter a trade, keyword, or NAICS code

How NAICS codes work in public bidding

You select NAICS codes when you register in SAM.gov and on state contractor portals. Federal small-business set-asides (8(a), HUBZone, SDVOSB, WOSB) and SBA size standards are applied per NAICS code, so the code you bid under determines whether you qualify as a small business. General contractors use the 236 and 237 series; specialty subcontractors use the 238 series.

Type a trade, keyword, or NAICS code above to search all construction codes — 236 (buildings), 237 (heavy/civil), 238 (specialty trades).

All Construction NAICS Codes

236 — Construction of Buildings

236115New Single-Family Housing Construction (except For-Sale Builders)

236116New Multifamily Housing Construction (except For-Sale Builders)

236117New Housing For-Sale Builders

236118Residential Remodelers

236210Industrial Building Construction

236220Commercial and Institutional Building Construction

237 — Heavy and Civil Engineering Construction

237110Water and Sewer Line and Related Structures Construction

237120Oil and Gas Pipeline and Related Structures Construction

237130Power and Communication Line and Related Structures Construction

237210Land Subdivision

237310Highway, Street, and Bridge Construction

237990Other Heavy and Civil Engineering Construction

238 — Specialty Trade Contractors

238110Poured Concrete Foundation and Structure Contractors

238120Structural Steel and Precast Concrete Contractors

238130Framing Contractors

238140Masonry Contractors

238150Glass and Glazing Contractors

238160Roofing Contractors

238170Siding Contractors

238190Other Foundation, Structure, and Building Exterior Contractors

238210Electrical Contractors and Other Wiring Installation Contractors

238220Plumbing, Heating, and Air-Conditioning Contractors

238290Other Building Equipment Contractors

238310Drywall and Insulation Contractors

238320Painting and Wall Covering Contractors

238330Flooring Contractors

238340Tile and Terrazzo Contractors

238350Finish Carpentry Contractors

238390Other Building Finishing Contractors

238910Site Preparation Contractors

238990All Other Specialty Trade Contractors

Example

An electrical subcontractor needs the right NAICS code to register in SAM.gov and filter public bids to their trade.

Search query"electrical"

Matched subsector238 — Specialty Trade Contractors

Code found238210 Electrical Contractors and Other Wiring Installation Contractors

SBA size standard$19.0M average annual receipts

How to Use This Tool

1Type your trade (e.g., "electrical"), a keyword (e.g., "paving"), or a NAICS code (e.g., "238210").
2Browse the grouped results by subsector — 236 (buildings), 237 (heavy/civil), 238 (specialty trades).
3Note the six-digit code, its GC-vs-subcontractor role, and the SBA small-business size standard.
4Use the code to register in SAM.gov, classify your bids, and check set-aside eligibility.

How to Apply the Results

Use your NAICS code to register in SAM.gov, classify your bids, and check small-business set-aside eligibility. Enter it on federal and state contractor registrations, and use it to filter public bid opportunities to the work you actually perform.

Frequently Asked Questions

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