NAICS Code for General Contractor Construction: The Complete Guide for Federal Bidders

A general contractor in construction typically registers under NAICS code 236220 (Commercial and Institutional Building Construction) or 236210 (Industrial Building Construction), depending on the types of projects they pursue. The specific code matters because federal agencies on SAM.gov filter solicitations by NAICS—choosing the wrong one means missing work you can actually do. Your NAICS classification also determines bonding requirements, small business size standards, and whether you compete as small or large for each opportunity.

What Is a NAICS Code and Why It Matters for Federal Work

A NAICS (North American Industry Classification System) code is a six-digit number assigned by the U.S. Census Bureau to classify business activities. For federal procurement, it is the single identifier that connects your firm to the solicitations you can bid. The General Services Administration, Department of Veterans Affairs, Department of Defense, and every other federal buyer use NAICS codes to organize opportunities. When a contracting officer publishes a solicitation on SAM.gov, they assign it one or more NAICS codes. Your SAM.gov registration must include the codes that match your business—otherwise, you won't see the work.

Many contractors underestimate this step and register with a single, broad NAICS code. That decision costs them 30–40% of available work in their actual capability area. Federal buyers are specific. A firm that can handle both commercial fit-outs and heavy industrial construction is leaving opportunities on the table by registering only 236220 when 236210 should also be active.

NAICS Codes for General Contractors: The Core Options

General contractors in construction work across several NAICS classifications. The right choice depends on the primary revenue stream and the types of clients and projects your firm targets.

Most full-service general contractors register with at least two codes—one primary and one or two secondary. A firm doing commercial renovations in office parks (236220) and occasional small industrial builds (236210) strengthens its SAM.gov profile by registering both. Federal buyers also use secondary NAICS codes when no primary code perfectly fits the work, so having options increases visibility.

How to Verify and Register Your NAICS Code on SAM.gov

Your NAICS registration lives in your SAM.gov entity record and is the foundation of your federal bidding presence. Here is how to ensure it is correct:

1. Log into SAM.gov with your entity administrator credentials. If you are not yet registered, create a free account and begin the entity registration process.
2. Navigate to the Business Information section and locate the NAICS codes field. You will see a space for a primary code and secondary codes.
3. Enter your primary NAICS code based on the category of work that generates the most revenue. If you are a general contractor primarily doing office and institutional renovations, 236220 is your primary.
4. Add secondary NAICS codes if your firm also performs work in other construction categories. The Census Bureau allows multiple codes per entity.
5. Confirm your small business status if applicable. The SAM.gov system uses NAICS codes to determine whether you meet the small business size standard ($45.5 million for most construction codes). If you are small and register under a code with a higher threshold, you may lose eligibility.
6. Save and certify your entity record. Changes take effect within 24 hours on SAM.gov search results.

Many contractors update their NAICS codes once and never revisit them. If your business mix shifts—for example, you expand into industrial work after five years of commercial builds—update SAM.gov proactively. Outdated NAICS registration is a silent cause of missed opportunities.

Common Mistakes in NAICS Code Selection

Federal buyers and contracting officers regularly see contractors register with the wrong NAICS code or too few. Here are the patterns that cost work:

Using only one code when the firm is multi-capability. A firm that does both commercial fit-outs and small industrial projects registers only 236220 and misses solicitations marked 236210. This is the most frequent error.

Registering under a too-broad specialty trade code instead of general contractor. Contractors who primarily perform general construction oversight but register under 238990 (All Other Specialty Trade Contractors) are categorized as specialty contractors rather than general contractors. This limits the solicitations they see and sometimes disqualifies them from general construction leads.

Ignoring small business size standards. Registering under a NAICS code with a $22.5 million small business threshold when your revenue is $40 million means you cannot bid set-asides for small businesses. You have to compete with all contractors, including large firms. It is worth understanding the thresholds for your codes and deciding whether you prefer to compete as small or large.

Not updating NAICS codes after business changes. A contractor shifts focus from new construction to renovation work but forgets to add or change their NAICS code registration. Federal buyers filtering for new construction (236115, 236117) or renovation contractors (specifically flagged in solicitation descriptions) won't find you.

Using NAICS Codes in Your Federal Bidding Strategy

Once your SAM.gov NAICS registration is accurate, the next step is monitoring solicitations that match those codes. Federal agencies publish thousands of opportunities each week. A general contractor in construction might see anywhere from 40 to 200 new solicitations per month for their NAICS codes, depending on the codes selected and geographic focus.

Tracking deadlines manually is impractical. Most deadlines cluster around T-21, T-13, T-7, and T-3 days before closing. Contracting officers publish amendments that reset or shift response dates. Proposal outlines require significant upfront research—identifying past agency selections, budget data, and incumbent contractors. A tool like BidWatch automates this by monitoring SAM.gov for your registered NAICS codes and keywords, tracking every response deadline and amendment, and sending alerts at T-21, T-13, T-7, and T-3 days. The free plan tracks three solicitations; paid plans begin at $12.99/month with a 14-day trial, giving your firm early-stage insight into matching opportunities.

The strategy itself is straightforward: register the NAICS codes that match your firm, monitor them regularly, set response timelines, and prioritize opportunities that align with your past wins and team capacity. Contractors that invest in accurate NAICS registration and consistent monitoring close 15–30% more federal work within 12 months.

FAQ: NAICS Codes and Federal Bidding

What's the difference between a primary and secondary NAICS code?

Your primary NAICS code represents your principal business activity—the category that generates the most revenue or defines your core identity as a contractor. Secondary codes represent significant but subsidiary business lines. Federal buyers may filter by primary code only or search across all codes. Registering secondary codes expands the solicitations available to your firm. If you are primarily 236220 but also perform industrial construction, register both so you see opportunities marked 236210.

Can I change my NAICS code after SAM.gov registration?

Yes. Changes take effect within 24 hours of certification in SAM.gov. However, changing your primary NAICS code can affect your small business status, bonding requirements, and past proposal history. Before changing, verify that the new code aligns with your business revenues and federal compliance obligations. Many contractors add secondary codes rather than changing primary codes to avoid disruption.

How many NAICS codes should I register?

There is no single answer. A specialized contractor in one niche might use one code. A full-service general contractor often uses two to four codes. The practical limit is based on accuracy—register only codes that truthfully describe work your firm performs or intends to pursue. Registering too many codes dilutes your firm's profile and can invite scrutiny from contracting officers questioning whether you are genuinely capable in all categories.

How do I find solicitations for my NAICS codes?

SAM.gov provides a free search tool. Log in, navigate to Opportunities, and filter by NAICS code. You can also set up a saved search. For active monitoring of new solicitations, amendments, and deadlines, many contracting firms use procurement management tools that monitor SAM.gov on their behalf. This is especially useful if you track multiple NAICS codes or geographic regions; manual checking often misses last-minute amendments or solicitations published outside typical business hours.