NAICS Code for Construction: 2026 Size Table and Steps

By Aoba Works · Published October 28, 2026 · 17 min read

How this guide was made: drafted with AI assistance from the official sources linked below, then passed an automated editorial check before publishing. Our process

• Naics Codes
• Sba Size Standards
• Set Asides
• Sam.gov

No single NAICS code covers all of construction. Construction is NAICS Sector 23, and inside it you choose a 6-digit code from three subsectors: 236 for building construction (general contractors and homebuilders), 237 for heavy and civil engineering, and 238 for specialty trades. Use the code that brings in the largest share of your receipts. The code you pick also sets your SBA size standard. Under the current table, most 236 and 237 codes allow $45 million in average annual receipts and most 238 trade codes allow $19 million (13 CFR 121.201, as of October 2026).

Which option is right for you?

Find your situation in the table, then open the page listed for it before you change anything in SAM.gov.

The reasons, one line each:

• Beginner: Start with one accurate primary code. Listing twenty codes does not make you more eligible, and you have to defend each one if your size is ever protested.
• Daily bidding work: Each solicitation names its own NAICS code, so you need every code you might bid under in SAM.gov, not only the primary.
• Budget: Census lookups, the SBA table and APEX counseling are free. Paid help is only worth considering if your revenue sits close to a size threshold.

What Is the NAICS Code for Construction? (Overview + How Sector 23 Is Organized)

The NAICS code for construction is Sector 23, which splits into three 3-digit subsectors and dozens of 6-digit industry codes. You register and bid under the 6-digit codes. "23" alone is never what goes on a SAM.gov profile or a solicitation.

Each subsector covers a different kind of work:

All size figures come from 13 CFR 121.201 (as of October 2026) and match the SBA table that took effect March 17, 2023 (SBA).

The line between 236 and 238 is responsibility. Census places firms that perform specialized work on commercial and institutional buildings, "generally on a subcontract basis," in Subsector 238 rather than 236220 (NAICS 236220 description). A firm that takes responsibility for the whole building belongs in 236. A firm that installs one system in someone else's building belongs in 238.

Pitfall: Some third-party lists print wrong size figures. For example, at least one 2026 guide lists 236118 at $22.0M. The regulation sets $45.0M for 236118, and $22.0M is actually the figure for 238290 (13 CFR 121.201). Before you rely on any number, check it against the regulation or the SBA table.

How to Choose the Right NAICS Code When Your Trade Spans Multiple Codes

Pick the code that brings in the largest share of your receipts. Don't pick the one that sounds most impressive, because the code decides which size standard applies to you. SBA looks at "the distribution of receipts, employees and costs of doing business among the different industries" for your most recently completed fiscal year to decide your primary industry (13 CFR 121.107).

Steps to pick your primary code

1. Pull last fiscal year's revenue by job type. Use your job-costing or accounting reports. Group every job into what you actually did: whole-building responsibility, civil/site work, or a single trade.
2. Look up each group's code. Open the Census NAICS search, choose the 2022 NAICS edition, and type a plain keyword such as "drywall" or "highway." Read the full definition and the cross-references, not only the title.
3. Rank the groups by receipts. The biggest group is your primary-code candidate. If two groups are close, compare employee hours and costs too, since SBA weighs those as well (13 CFR 121.107).
4. Check each code's size standard. Find each code in the SBA table. Compare it with your average annual receipts, which for a firm 5+ years old is total receipts over the last 5 completed fiscal years divided by 5 (13 CFR 121.104). Count affiliates' receipts too.
5. Enter the codes in SAM.gov. Log in, open your entity, choose Update Entity Registration, go to the Goods and Services section, add each 6-digit NAICS code, and mark one as primary (SmallGovCon). Our SAM.gov registration guide walks through the rest of the record.
6. Add secondary codes only for work you can actually perform. Each code you list is a claim you may have to back up.

Worked example

This example is for illustration only. A firm averages $24M a year. Last year's revenue was 60% commercial building jobs where it was the prime, 30% self-performed electrical subcontracts, and 10% small residential remodels.

• Primary: 236220, which has a $45.0M standard. The firm is small under it.
• Secondary: 238210 Electrical Contractors, which has a $19.0M standard. The firm is not small under it, because size is measured on the whole firm's receipts, not just the electrical slice.
• Secondary: 236118, which has a $45.0M standard. The firm is small under it.

So the firm can compete for small business set-asides coded 236220 or 236118. It cannot compete for an electrical set-aside coded 238210, even though electrical is real work it performs. Picking codes is a two-way decision: the code has to match the work, and your size has to fit under it.

Common mistakes and fixes

• Mistake: Making 238xxx your primary because you started out as a trade sub, even though most revenue now comes from GC work. Fix: Recheck your revenue mix every year when you renew your SAM registration.
• Mistake: Assuming the primary code decides every bid. Fix: For a specific contract, the contracting officer names the governing code (see the last main section below).
• Mistake: Forgetting affiliates. Fix: Add the receipts of any company under common control before you compare against the standard.

What Is the NAICS Code for a Construction Company (General Contractor)?

For a construction company that takes responsibility for whole buildings, the code is usually 236220 (commercial and institutional) or one of 236115–236118 (residential). Industrial plants use 236210. Pick based on what you build, not on the name of your company.

Source for sizes: 13 CFR 121.201, as of October 2026.

Federal building work (renovating a VA clinic, an Army reserve center or a courthouse) is coded 236220 in most solicitations. The Census definition covers new work, additions, alterations, maintenance and repairs of commercial and institutional buildings (NAICS 236220). That is why 236220 tends to be the main code for a federal GC even when its jobs are renovations and not ground-up builds.

Here is an example. A three-person GC that mostly does tenant improvements and small renovations for federal agencies would normally pick 236220 as primary. It would add 236118 only if residential remodeling is a real revenue line.

Pitfall: A holding company or "construction business" that just owns subsidiaries doesn't get a construction code automatically. The code belongs to the entity that does the work and gets the receipts.

NAICS Code for Residential Construction vs. Commercial Construction

Residential construction uses 236115–236118, and commercial construction uses 236220. Today all five share a $45.0M size standard (13 CFR 121.201). The difference that matters for bidding is which code agencies actually put on solicitations.

On August 20, 2026, SBA proposed collapsing nearly 1,000 six-digit size standards into 338 and moving construction to employee-based standards. Under that proposal, 236220 would change from $45M to 600 employees (Thompson Hine; Schoonover & Moriarty). Comments closed September 21, 2026. As of October 2026 it is still a proposal, so the receipts-based numbers in this guide are the ones that apply. Track the docket at Regulations.gov SBA-2026-0199.

Pitfall: Builders sometimes code multifamily work as 236220 because the building "looks commercial." Census treats multifamily housing as residential (236116). Mixed-use buildings are judged by their main purpose. If you're unsure, read the cross-references in the Census definition before you choose.

What Is the NAICS Code for Construction Management and Construction Project Management?

For construction management of commercial and institutional buildings, the code is 236220 if the firm takes on construction responsibility. Census lists "Construction management, commercial and institutional building" as an index entry under 236220 (NAICS 236220 index). A firm that only advises the owner, without holding the trade contracts or the construction risk, usually fits a professional-services code instead.

How to tell which applies:

• CM at-risk or CM/GC: You hold the subcontracts, guarantee a price and carry schedule risk. Use 236220, or the matching 236/237 code for the type of project.
• CM-agent or owner's representative with engineering content (reviewing designs, checking technical submittals, inspecting during construction): 541330 Engineering Services. Its Census definition includes "provision of technical services during the construction or installation phase" (NAICS 541330). Size standard: $25.5M (13 CFR 121.201).
• Project management focused on schedules, budgets and administration, without engineering: 541611 Administrative Management and General Management Consulting Services, with a $24.5M size standard (13 CFR 121.201).

Here is an example. A firm hired by a Navy installation to manage a GC's schedule and pay applications, which never signs a subcontract, would look at 541330 or 541611. A firm that holds a guaranteed maximum price on the same project would use 236220.

Pitfall: Both 541330 and 541611 have lower size ceilings than 236220. A $30M firm that is small under 236220 is other-than-small under 541330's base $25.5M standard. Check before you change codes.

What Is the NAICS Code for Construction Consulting and Construction Consulting Services?

Construction consulting with no hands-on building usually falls under 541330 Engineering Services when the work is technical, or 541611 when it is managerial. Neither is a Sector 23 code, so construction set-asides coded 236/237/238 don't apply to this work.

Steps to place a consulting service

1. Write one sentence describing what the client pays for. For example: "We review structural drawings for code compliance." This example is illustrative only.
2. Ask whether engineering judgment is the product. If yes, use 541330. Its definition covers advice, feasibility studies, plans and designs, construction-phase technical services, and inspection of engineering projects (NAICS 541330).
3. If the product is organizing, planning or administration, use 541611 ($24.5M).
4. If the product is design of buildings, look at 541310 Architectural Services ($12.5M), which has a much lower ceiling (13 CFR 121.201).
5. Check the 541330 exceptions. Military and aerospace equipment engineering, Energy Policy Act work and marine engineering each carry a $47.0M standard instead of $25.5M (13 CFR 121.201). Those exceptions only apply when the solicitation says so.

One thing to watch: SBA's August 2026 proposal would remove these 541330 sub-industry exceptions and would move 541611 to a much higher receipts figure under a combined 5416 group (Schoonover & Moriarty). Nothing changes until a final rule is published.

NAICS Code for Construction Cost Estimating

Construction cost estimating sold as a standalone service is indexed by Census under 541990 All Other Professional, Scientific, and Technical Services (Ask Kodiak NAICS index). It has a $19.5M size standard (13 CFR 121.201). Cost engineering done inside a broader engineering engagement fits 541330.

The plan for this guide started with a common assumption that estimating sits under 541350. It doesn't. 541350 is Building Inspection Services, a separate activity with an $11.5M standard (13 CFR 121.201). Use 541350 only if inspection is the main thing you sell.

Here is an example. An estimator who prepares independent government cost estimates (IGCEs) for an agency under a services contract would list 541990, and 541330 if engineers sign the work.

Pitfall: Don't add 541990 just because your GC does estimating internally. You only list a code for services you sell to clients.

NAICS Code for Interior Construction and Specialty Trade Work

Interior construction usually maps to a Specialty Trade Contractor code in the 2383xx group (Building Finishing Contractors). The exact code depends on the trade. A firm that takes responsibility for a whole interior build-out as prime is doing 236220 work instead.

Sizes: 13 CFR 121.201, as of October 2026.

Here is an example. A drywall and acoustical ceiling firm uses 238310. If it starts taking full office build-outs where it hires the electrician, painter and flooring sub, that revenue becomes 236220 work. Once that share is the largest, its primary code should change.

The 238 codes also change how much you can subcontract on a set-aside. A specialty trade prime may pay non-similarly-situated firms no more than 75% of the contract amount, compared with 85% for general construction. Material costs are excluded in both cases (13 CFR 125.6). For how these limits play out, see our 51 rule checklist.

What Is the NAICS Code for Construction Services and Construction Work (General Catch-All Searches)?

There is no NAICS code called "construction services" or "construction work." Those phrases map to whichever building, civil or specialty-trade code matches the actual scope. When a contracting officer buys "construction services," they still have to pick one 6-digit code.

Steps to find the code for a vague scope

1. List the work items in the scope (for example: demolition, new roof, HVAC replacement, interior finishes).
2. Estimate each item's share of contract value. Procurements are classified by "the component which accounts for the greatest percentage of contract value" (13 CFR 121.402).
3. Code the largest component. A job that is 70% roofing is coded 238160. A job with many trades under one prime is usually coded 236220.
4. Check facility-maintenance bundles. If the scope is ongoing building operations, it may be coded 561210 Facilities Support Services ($47.0M). The SBA footnote says that if one specific industry makes up 50% or more of the value, that industry's code applies instead (13 CFR 121.201).

Pitfall: Typing "construction" into the Census search returns dozens of results. Search for the specific activity ("site preparation," "water main," "roof") instead. Site preparation is 238910 ($19.0M), and water and sewer line work is 237110 ($45.0M).

How Your NAICS Code Choice Changes Your SBA Size Standard and Set-Aside Eligibility

For each contract, the size standard you must meet belongs to the NAICS code in that solicitation. The contracting officer designates "the single NAICS code which best describes the principal purpose" of the acquisition (13 CFR 121.402). In Sector 23, that code's ceiling ranges from $19.0M to $45.0M.

The thresholds come from 13 CFR 121.201. The receipt amounts are examples.

What this means for your bids:

• SAM.gov is checked per code. SAM profiles show small business status against the size standards. After SBA changed the table, firms had to update their SAM registrations before their status refreshed (SBA). If a code isn't in your profile, you can't certify as small under it.
• Dredging has an extra test. To count as small on a dredging procurement, you and similarly situated subcontractors must perform at least 40% of the volume dredged with your own equipment or equipment owned by another small dredging concern (13 CFR 121.201).
• Set-aside type sits on top of size. 8(a), WOSB, HUBZone and SDVOSB set-asides all require you to be small under the solicitation's code first. See our SBA size standards by NAICS guide and the total vs partial set-aside checklist.

If the solicitation's code looks wrong

Any interested party adversely affected by a NAICS code designation may appeal to SBA's Office of Hearings and Appeals (OHA). The appeal must be filed within 10 calendar days after the solicitation (or the amendment changing the code) is issued. Late appeals are dismissed. A timely appeal makes the contracting officer stay the closing date (13 CFR 121.1103).

Here is an example. A renovation that is mostly HVAC replacement is coded 236220 ($45M). A $20M HVAC contractor is small under either code. But if larger general contractors are using 236220 to compete against small mechanical firms, a 238220 code would narrow the field to firms under $19M. Whether an appeal is worth filing depends on whether the scope really is mostly one trade. It is not a tactic for removing competitors.

Before an RFP comes out, you can raise a coding concern informally. Our sources sought response template shows where to suggest a NAICS code.

Next steps

Start with your own revenue figures. Most code mistakes come from guessing which code fits instead of measuring where your receipts come from.

Today, on your own:

1. Export last fiscal year's revenue by job type, calculate the share for each code, and set the largest as your primary.
2. Calculate your 5-year average annual receipts, including affiliates, and compare it with every code you plan to list in the SBA table.
3. Open SAM.gov, go to Update Entity Registration, then Goods and Services, and remove any codes you can't perform or aren't small under.

If you'd rather not do it alone:

• APEX Accelerators (formerly PTACs) offer government contracting counseling, including NAICS selection and SAM.gov review, generally at no cost (as of October 2026; check the official page). This suits first-time bidders and firms clearly under the thresholds. It is less useful if you need legal advice on an affiliation or size protest question, because counselors are not your lawyers, and appointment wait times vary by location.
• A government contracts attorney makes sense when your receipts are within a few million dollars of a threshold, or when you are considering an OHA NAICS appeal with its 10-day deadline. Fees vary widely and are usually hourly, so get a written estimate first. A firm well below every relevant standard usually doesn't need one.

Related guides on Set-Aside Brief:

• SBA Size Standards by NAICS: 2026 Table, Steps & Appeals
• SAM.gov Registration Guide: 7 Steps From UEI to Active
• How to Bid on Government Contracts: 7 Steps, 2026 Costs
• Capability Statement Example: 5 Sections Buyers Read First

FAQ

What is the NAICS code for a construction company?

Most construction companies that take responsibility for whole buildings use 236220 for commercial and institutional work or 236115–236118 for residential work. Each of these has a $45.0M size standard (13 CFR 121.201). Trade-focused companies use a 238xxx code, and civil firms use a 237xxx code. Your primary code should match your largest source of receipts.

What is the NAICS code for interior construction?

Interior finish trades fall under Specialty Trade Contractors: 238310 for drywall, 238320 for painting, 238330 for flooring, 238340 for tile and 238350 for finish carpentry. Most have a $19.0M standard (13 CFR 121.201). If you manage the whole interior build-out as prime, that work is 236220.

What is the NAICS code for commercial construction?

Commercial construction is 236220, Commercial and Institutional Building Construction. It covers new work, additions, alterations, maintenance and repairs (NAICS 236220). Its current size standard is $45.0M. SBA's August 2026 proposal would change it to 600 employees, but that is not final.

What is the NAICS code for construction project management?

If you hold the construction contracts and carry the risk, Census indexes construction management of commercial buildings under 236220. If you only manage or advise for the owner, 541330 ($25.5M) or 541611 ($24.5M) usually fits better (13 CFR 121.201).

What is the NAICS code for construction work?

"Construction work" doesn't have its own code. The code depends on the largest component of the work by contract value (13 CFR 121.402). Look up the specific activity in the Census NAICS search and use that 6-digit code.

Sources

• 13 CFR 121.201 – Size standards by NAICS industry (Cornell LII)
• 13 CFR 121.104 – Annual receipts calculation
• 13 CFR 121.107 – Primary industry determination
• 13 CFR 121.402 – NAICS designation for procurements
• 13 CFR 121.1103 – NAICS code appeals
• 13 CFR 125.6 – Limitations on subcontracting
• SBA – Table of size standards (effective March 17, 2023)
• U.S. Census Bureau – NAICS search
• NAICS 236220 description and index entries
• NAICS 541330 description
• Ask Kodiak – Construction estimation services (541990)
• Thompson Hine – SBA proposed size standards overhaul (August 2026)
• Schoonover & Moriarty – SBA proposed size standards
• Regulations.gov – Docket SBA-2026-0199
• SmallGovCon – Registering in SAM.gov
• APEX Accelerators
• ConstructionBids.ai – Construction NAICS list (example of a third-party size error)

Spotted something out of date or wrong? Tell us at shigoto.ai.note@gmail.com. Guides are re-checked against official sources on a rolling schedule.