Lintel logoLintel

Construction NAICS Code: Complete List for Contractors and Project Teams

9 min read

Construction NAICS Code: Complete List for Contractors and Project Teams

Every federal bid, SBA loan application, and bonding form asks for your construction NAICS code. Get it wrong and you may be disqualified from a set-aside, misclassified for size standards, or flagged during a compliance audit. This reference covers every major NAICS code in Sector 23, how to choose the right one for your trade, and why accurate classification matters beyond registration forms. If you are a GC, estimator, or specialty contractor who needs a fast answer, start here.

What Is a NAICS Code and Why Does It Matter in Construction?

The North American Industry Classification System (NAICS) is the federal standard for classifying businesses by economic activity. Codes are six digits. The first two digits identify the sector. For construction, that is always 23. Digits three through six narrow the classification to subsector, industry group, and specific industry.

How NAICS Codes Are Used in Bidding, Bonding, and Compliance

NAICS codes are not administrative formalities. They determine:

  • Federal set-aside eligibility. SAM.gov registrations tie directly to NAICS codes. A code mismatch can exclude you from a small business set-aside even if you qualify by revenue.
  • SBA size standards. Revenue and employee thresholds vary by NAICS code. A general contractor classified under 236220 has a different size standard than one under 237310.
  • Bonding and insurance classification. Surety underwriters and insurers use NAICS codes to assess risk. Misclassification can produce incorrect premiums or denied claims.
  • Prequalification. Many owners and CMs filter contractor databases by NAICS code. If yours does not match your actual scope, you may not appear in the right search results.

Where Construction Falls in the NAICS Hierarchy (Sector 23)

Sector 23 contains three subsectors:

| Subsector | Range | Description | |-----------|-------|-------------| | 236 | 2361–2362 | Construction of Buildings | | 237 | 2371–2379 | Heavy and Civil Engineering Construction | | 238 | 2381–2389 | Specialty Trade Contractors |

Complete List of Construction NAICS Codes by Trade and Sector

Building Construction NAICS Codes (2361–2362)

These codes apply to contractors who manage overall construction of residential or commercial structures.

  • 236115 - New Single-Family Housing Construction (except Operative Builders)
  • 236116 - New Multifamily Housing Construction (except Operative Builders)
  • 236117 - New Housing Operative Builders
  • 236118 - Residential Remodelers
  • 236210 - Industrial Building Construction
  • 236220 - Commercial and Institutional Building Construction

236220 is the most common construction NAICS code for commercial GCs. It covers offices, warehouses, schools, hospitals, and retail. If you are bidding a LEED-certified office tower or a public school addition, this is almost certainly your primary code.

Heavy and Civil Engineering Construction NAICS Codes (237)

  • 237110 - Water and Sewer Line and Related Structures Construction
  • 237120 - Oil and Gas Pipeline and Related Structures Construction
  • 237130 - Power and Communication Line and Related Structures Construction
  • 237210 - Land Subdivision
  • 237310 - Highway, Street, and Bridge Construction
  • 237990 - Other Heavy and Civil Engineering Construction

Highway and bridge contractors most often register under 237310. Utility contractors installing water mains or force mains use 237110.

Specialty Trade Contractors NAICS Codes (238)

This is where most subcontractors land. The 238 subsector is the largest in Sector 23 by firm count.

  • 238110 - Poured Concrete Foundation and Structure Contractors
  • 238120 - Structural Steel and Precast Concrete Contractors
  • 238130 - Framing Contractors
  • 238140 - Masonry Contractors
  • 238150 - Glass and Glazing Contractors
  • 238160 - Roofing Contractors
  • 238170 - Siding Contractors
  • 238190 - Other Foundation, Structure, and Building Exterior Contractors
  • 238210 - Electrical Contractors and Other Wiring Installation Contractors
  • 238220 - Plumbing, Heating, and Air-Conditioning Contractors
  • 238290 - Other Building Equipment Contractors
  • 238310 - Drywall and Insulation Contractors
  • 238320 - Painting and Wall Covering Contractors
  • 238330 - Flooring Contractors
  • 238340 - Tile and Terrazzo Contractors
  • 238350 - Finish Carpentry Contractors
  • 238390 - Other Building Finishing Contractors
  • 238910 - Site Preparation Contractors
  • 238990 - All Other Specialty Trade Contractors

Electrical, Plumbing, and Mechanical Specialty Codes

Three codes deserve extra attention because they generate the most classification confusion:

  • 238210 covers electrical rough-in, panel work, low-voltage systems, and fire alarm installation.
  • 238220 covers plumbing rough-in, HVAC, piping, and mechanical systems. A mechanical contractor installing hydronic heating and a plumber running domestic water both land here.
  • 238290 catches specialty equipment not covered by 238210 or 238220, including elevator installation and boiler work.

Contractors performing both electrical and mechanical work often register multiple codes. That overlap is where scope gaps and contradictions most frequently appear in project documents, a point covered in the documentation section below.

How to Find the Right NAICS Code for Your Construction Business

Using the Official NAICS Search Tool

The Census Bureau maintains the official NAICS search at census.gov/naics. Enter a keyword describing your primary work (e.g., "roofing," "electrical," "concrete"). The tool returns candidate codes with definitions. Read the definitions and the "illustrative examples" section before selecting.

Choosing Between Multiple Applicable Codes

Your primary NAICS code should reflect the majority of your revenue. If 60% of your volume is commercial tenant improvement and 40% is light industrial, 236220 is your primary code. Secondary codes can be added in SAM.gov and most prequalification databases.

When Your Work Spans More Than One NAICS Category

Design-build firms, construction managers, and GCs self-performing specialty work often span subsectors. Register all codes that describe material revenue streams. During prequalification, list your primary code first and secondary codes in descending order of revenue share. Bonding agents will want to see this split when underwriting.

Construction NAICS Codes and Project Documentation

How NAICS Classification Affects Contract Scope Definition

NAICS codes define the business. Project contracts and drawing sets define the scope. The two should align. A specialty contractor registered under 238220 taking on a project where the spec sections for mechanical (Division 23) and plumbing (Division 22) overlap with low-voltage controls (Division 25) needs explicit scope language in the contract to avoid fielding RFIs for work that falls between trades.

Scope Gaps That Arise When Trades Are Misclassified

When a contractor's NAICS registration does not match their actual field capabilities, scope gaps follow. Common patterns:

  • A framing contractor (238130) subcontracting sheathing and exterior insulation work that belongs to a roofing or siding contractor (238160/238170), with no written scope delineation
  • A mechanical contractor (238220) assigned BAS controls work without a written boundary in the spec sections against the low-voltage electrical contractor (238210)
  • An electrical contractor assuming fire alarm rough-in is excluded because the GC registered a separate alarm sub, but neither subcontract addresses it explicitly

Each of these patterns produces RFIs, delays, and potential change orders.

Lintel analysis of construction document sets finds that trades classified under multiple overlapping NAICS codes - such as mechanical and electrical specialty work - account for a disproportionate share of scope gap RFIs, averaging 3.2 unresolved contradictions per drawing set in those divisions.

How Lintel Flags Scope Gaps Before They Become Field Problems

Lintel reads the full document set, cross-references scope language in the contract against spec sections and drawing notes, and surfaces contradictions between overlapping trade divisions before they reach the field. For projects with mechanical and electrical specialty contractors, Lintel specifically checks Division 22, 23, 25, and 26 boundaries against sheet notes and equipment schedules. For more detail on how document review catches these issues early, see our construction document review resources.

Common NAICS Code Mistakes Contractors Make

  1. Using 236220 for residential work. Residential remodelers belong under 236118, not 236220. The size standards and set-aside categories differ.
  2. Defaulting to 238990 when a specific code exists. "All Other Specialty Trade Contractors" is a catch-all. If your work fits 238210 through 238390, use the specific code.
  3. Not updating codes after scope expansion. A concrete subcontractor who adds self-perform structural steel should add 238120 to their SAM.gov registration.
  4. Applying a GC code to a specialty firm. A roofing contractor registering under 236220 because they work on commercial buildings will be misclassified. The work type defines the code, not the building type.
  5. Ignoring secondary codes on federal bids. Many set-aside solicitations require the NAICS code to match the solicitation's designated code exactly. If yours does not match, you cannot bid, regardless of qualifications.

Quick-Reference Table: Top Construction NAICS Codes

| NAICS Code | Description | Typical User | |------------|-------------|--------------| | 236115 | New Single-Family Housing Construction | Custom home builders | | 236118 | Residential Remodelers | Residential GCs and remodelers | | 236220 | Commercial and Institutional Building Construction | Commercial GCs | | 237110 | Water and Sewer Line Construction | Utility contractors | | 237310 | Highway, Street, and Bridge Construction | Civil contractors | | 238110 | Poured Concrete Foundation Contractors | Concrete subs | | 238130 | Framing Contractors | Wood framing subs | | 238160 | Roofing Contractors | Roofing subs | | 238210 | Electrical Contractors | Electrical subs | | 238220 | Plumbing, Heating, and AC Contractors | Mechanical/plumbing subs | | 238310 | Drywall and Insulation Contractors | Drywall subs | | 238910 | Site Preparation Contractors | Earthwork and demo subs |

FAQ

What is the NAICS code for general contractors in construction?

Commercial GCs most commonly use 236220 (Commercial and Institutional Building Construction). Residential GCs building new single-family homes use 236115. Residential remodelers use 236118. Your primary code should reflect the building type and project type that generates the majority of your revenue.

What is the difference between NAICS codes 2361 and 2362?

2361 covers residential building construction, including single-family, multifamily, and operative builders. 2362 covers nonresidential building construction, including industrial and commercial structures. The distinction matters for SBA size standards and federal set-aside eligibility, which differ between residential and commercial classifications.

Do subcontractors use a different NAICS code than general contractors?

Yes. Subcontractors use Subsector 238 (Specialty Trade Contractors). GCs managing overall project delivery use Subsector 236 (Building Construction) or 237 (Heavy and Civil). The codes reflect the type of work performed, not the contractual relationship to the owner.

See what Lintel finds in your document set - Book a demo

See what Lintel finds in your document set.

Book a demo