What NAICS code do you need for government contracts?

NAICS codes — the North American Industry Classification System — are how government agencies classify the type of work in a contract opportunity. They are also how buyers filter which businesses to invite to compete. If your business is monitoring the wrong NAICS codes, you are missing relevant opportunities and spending time on ones that do not fit.

Understanding which codes matter for your business is one of the most practical steps a small business can take before entering government contracting.

What a NAICS code is

A NAICS code is a six-digit number that classifies industries and business activities. The federal government uses NAICS codes to organize solicitations, determine small business size standards, and apply set-aside designations. Each code corresponds to a specific type of work — from custom software development to janitorial services to highway construction.

When a contracting officer posts an opportunity, they assign a NAICS code that describes the primary work being purchased. That code determines which businesses the opportunity is visible to in a capability-based search.

Primary NAICS vs additional NAICS codes

Your primary NAICS code describes the main line of business — the service or product that represents the majority of your revenue or core expertise. This is the code most closely tied to your business identity and size classification.

Your additional NAICS codes cover related services your business can also deliver. A cybersecurity firm, for example, might have a primary code in IT security services and additional codes in network infrastructure, cloud computing, and technical consulting.

Monitoring multiple relevant codes — rather than just the primary — gives your business a broader view of opportunities without losing the focus that capability-based searching requires.

Common NAICS codes for service-based small businesses

How to find your NAICS codes

The most direct way to confirm your NAICS classification is to review your SAM.gov registration. Your registered codes are the ones government buyers see when they search for qualified vendors. If your codes are outdated or missing key services your business now provides, updating your SAM.gov profile is a practical first step.

To identify which codes best match your services, consider:

• What work do your clients actually pay you to do?
• What type of contracts have similar businesses been awarded in your industry?
• Which codes appear on opportunities you already know are relevant to your business?
• Are there adjacent service categories where your team has relevant experience?

NAICS codes and size standards

Each NAICS code has a corresponding SBA size standard — either a revenue threshold or an employee count — that determines whether a business qualifies as small for federal contracting purposes. The size standard varies by code. A business may be considered small under one code and not under another.

This matters because many contract opportunities are restricted to small businesses. If your business is pursuing a set-aside and your revenue exceeds the size standard for that NAICS code, you may be disqualified from competing.

Always verify the size standard for the specific NAICS code tied to an opportunity before submitting a response.

How CapGen uses NAICS codes

CapGen connects a business capability profile to relevant NAICS categories, then monitors live government opportunities against those codes. Instead of searching by keyword, the business profile drives the match — and opportunities are reviewed for fit, set-aside eligibility, deadline risk, and pursuit readiness before they reach the business owner.