NAICS Codes for Government Contracting: How to Find Yours

Every federal contract is assigned a NAICS code that identifies the industry of the work being performed. Your NAICS code determines which contracts you're eligible to bid on, what small business size standard applies to you, and which competitors you face. Getting your NAICS code right is one of the first decisions you make as a federal contractor, and getting it wrong can cost you opportunities.

What Is a NAICS Code?

The North American Industry Classification System (NAICS) is a standardized system used by the U.S., Canada, and Mexico to classify business establishments by their economic activity. Each code is a 6-digit number that progressively narrows from sector to subsector to industry group to specific industry.

For example:

• 54 — Professional, Scientific, and Technical Services (sector)
• 5415 — Computer Systems Design and Related Services (subsector)
• 541512 — Computer Systems Design Services (full code)

In federal contracting, the contracting officer assigns a NAICS code to each solicitation based on the primary work being performed. The assigned code determines the small business size standard for that contract.

Why NAICS Codes Matter for Federal Contractors

NAICS codes affect your federal contracting business in three ways:

1. Small business eligibility. Each NAICS code has a size standard (either revenue or employee count) that determines whether your company qualifies as a small business for that type of work. For example, NAICS 541512 (Computer Systems Design) has a size standard of $34 million in annual revenue, while NAICS 236220 (Commercial Building Construction) has a standard of $45 million.
2. Contract discovery. When you search for opportunities on SAM.gov, you filter by NAICS code. Registering under the right codes ensures you see relevant solicitations.
3. Market intelligence. Understanding federal spending in your NAICS code helps you size the market, identify top agencies, and find competitors. Browse federal spending by NAICS code on ContractCliff.

How to Find Your NAICS Code

Most businesses map to 2-5 NAICS codes depending on the services or products they offer. Here is how to identify the right ones:

1. Start with what you do. Describe your primary business activity in plain language. If you provide IT staffing, that is NAICS 561311. If you build software, that is NAICS 541511 or 541512 depending on whether it is custom or packaged.
2. Check the NAICS directory. The Census Bureau publishes the official NAICS code list at naics.com. Search by keyword to find codes that match your work.
3. Look at what competitors use. Search for competitors on ContractCliff and see which NAICS codes appear in their contract awards. If similar companies win contracts under certain codes, those are likely relevant to you.
4. Check the spending. Some NAICS codes have billions in federal spending while others have almost none. Browse NAICS spending on ContractCliff to see which codes have the most contract activity.
5. Register for multiple codes. In SAM.gov you can list multiple NAICS codes. This does not limit your ability to bid on other codes, but it helps agencies find you during market research.

Top NAICS Codes by Federal Contract Spending

Certain NAICS codes receive significantly more federal contract dollars than others. The highest-spending codes reflect the government's biggest procurement categories:

• 336411 — Aircraft Manufacturing (defense platforms)
• 541330 — Engineering Services (infrastructure and defense systems)
• 541512 — Computer Systems Design (IT modernization)
• 336611 — Ship Building and Repairing (Navy)
• 561210 — Facilities Support Services (base operations)
• 541511 — Custom Computer Programming Services
• 336414 — Guided Missile and Space Vehicle Manufacturing
• 541715 — R&D in Physical, Engineering, and Life Sciences

Defense-heavy codes dominate the top of the list, but civilian agencies also drive significant spending in categories like 721110 — Hotels and Motels (government travel and lodging contracts) and 561720 — Janitorial Services (facility maintenance across federal buildings).

View the complete ranking with contract counts and dollar amounts on the NAICS browse page.

NAICS Codes and Set-Asides

When a contract is set aside for small businesses, the size standard is determined by the NAICS code assigned to that contract. This means the same company could be "small" under one NAICS code and "large" under another, depending on the size standard for each.

If you are near the size standard threshold, choosing which NAICS codes to pursue becomes a strategic decision. Some contractors intentionally pursue work under codes where they still qualify as small, even if a different code might be a more precise description of the work.

Common NAICS Code Mistakes

• Choosing too broad a code. Using a 4-digit code when a 6-digit code is more accurate can put you in a larger competitive pool and a different size standard.
• Ignoring spending data. Some NAICS codes look relevant but have minimal federal spending. Check the actual spending before targeting a code.
• Not updating SAM.gov. If you expand your services, update your NAICS codes in SAM.gov. Agencies doing market research may filter by NAICS to find potential vendors.
• Protesting the wrong code. Contractors can protest the NAICS code assigned to a solicitation if they believe it is incorrect. This can change the size standard and affect small business eligibility.

Using NAICS Data for Market Intelligence

Beyond registration, NAICS codes are a powerful market research tool. ContractCliff's NAICS pages show:

• Total federal spending per NAICS code
• Number of contract awards
• Top agencies buying in each category
• Top contractors winning in each category
• Contract cliffs by NAICS code (expiring opportunities)

This data helps you size your addressable market, identify which agencies to target, and find incumbents whose contracts are expiring.