Understanding NAICS Codes for Government Contracting

What is a NAICS Code?

NAICS (North American Industry Classification System) is the standard system used by the United States, Canada, and Mexico to classify business establishments by their primary type of economic activity. Each code is a 6-digit number that describes a specific industry or business function.

In federal contracting, every solicitation is assigned a primary NAICS code. This code determines two critical things: which businesses are eligible to bid (based on size standards), and how the contract is classified in procurement databases. When contracting officers search for vendors, they frequently filter by NAICS code.

The NAICS system is hierarchical. The first two digits represent the economic sector (e.g., 54 = Professional, Scientific, and Technical Services). Each additional digit narrows the classification. For example, 541512 specifically covers Computer Systems Design Services.

How NAICS Codes Connect to Size Standards

Every NAICS code has an associated SBA size standard that determines whether your business qualifies as "small" for contracts under that code. Size standards are measured in one of two ways: average annual revenue (typically over the past 5 years) or number of employees (averaged over 12 months).

This is critical because small business set-aside contracts — which represent billions in annual federal spending — are only open to firms that meet the size standard for the solicitation's NAICS code. If the contract's NAICS code has a $16.5 million revenue threshold and your average annual revenue is $20 million, you're not eligible for that set-aside even if you're small under other codes.

How to Find the Right NAICS Codes for Your Business

Start with the official NAICS search tool at census.gov/naics. Enter keywords that describe your products or services, and the tool will return matching codes. You should also review the detailed code descriptions to ensure they accurately match your capabilities.

Here's a practical approach: search SAM.gov for contracts similar to the work you do. Look at the NAICS codes assigned to those solicitations. If companies like yours are winning contracts under specific codes, those are likely relevant to your business too.

Select every NAICS code that legitimately describes work you can perform. There's no penalty for having multiple codes in your SAM.gov profile, and each code opens access to a different pool of opportunities. However, don't add codes for work you can't actually deliver — this can cause problems during audits or performance evaluations.

Your SAM.gov registration allows you to list multiple NAICS codes. You must designate one as your primary code, which is used for your overall small business determination.

Strategic NAICS Code Selection

Smart contractors think about NAICS codes strategically, not just descriptively. Consider which codes have the most active solicitations in your target agencies, where the size standards give you the most room to grow, and where the competition is thinnest.

For example, if you provide IT services, you might qualify under 541511 (Custom Programming), 541512 (Computer Systems Design), 541519 (Other Computer Services), and 518210 (Cloud Computing). Each code may have different competitors, different size standards, and different volumes of opportunities. Your CAGE code and SAM.gov profile should reflect all legitimate codes.

Tools like GovCon AI let you track opportunities across all your NAICS codes simultaneously, so you never miss a match regardless of which code the contracting officer assigned.

NAICS Code Challenges and Protests

If you believe a contracting officer assigned the wrong NAICS code to a solicitation (which affects whether it's set aside for small businesses or which size standard applies), you can file a NAICS code challenge with the SBA Office of Hearings and Appeals. This must be done within specific timeframes — typically before the closing date of the solicitation.

NAICS challenges are more common than you might think, and they can change the competitive landscape of a procurement entirely. If a code change results in a different size standard, it can open the door for more small businesses to compete.