How to Find and Choose the Right NAICS Codes for Your Business

To find your NAICS code, search the free official NAICS code lookup at census.gov for words that describe what you sell, then read each code's full definition to confirm it fits. To choose the right codes for federal contracting, mark the one that covers most of your business as your primary, add every related code for work you can actually do, and check each code's size standard, because that's what decides whether you count as small.

What is a NAICS code?

A NAICS code is a six-digit number that identifies an industry under the North American Industry Classification System, which the United States, Canada, and Mexico developed together. The federal government uses these codes to sort businesses and contracts by the kind of work involved. The Small Business Administration (SBA) and SAM.gov currently use the 2022 edition, called NAICS 2022.

The digits run from general to specific. Here's the code for janitorial services:

For federal contracting, you always work with the full six-digit code. So when you ask "what is my NAICS code?" or "what NAICS code is my business?", the answer is the six-digit code whose definition best matches what your business does. For SAM.gov, no one assigns it to you. You choose it.

NAICS vs. SIC codes

SIC (Standard Industrial Classification) codes are the older system. According to the Bureau of Labor Statistics, SIC was retired and replaced by NAICS, with the notice issued in April 1997, and NAICS codes run up to six digits instead of SIC's four. SAM.gov and SBA size standards use NAICS, so that's the code you need.

How to find your NAICS code with the official lookup

1. List what you actually sell. Write down your main services or products, plus related work you do regularly. Be specific: "office cleaning" and "floor refinishing," not just "cleaning."
2. Search the NAICS code lookup at census.gov/naics. Try several keywords for each item. Use the 2022 codes, since that's the version SBA and SAM.gov use.
3. Read the full definition, not just the title. Definitions say what's included and often point you to a different code for related work. For example, 561720 (Janitorial Services) covers cleaning building interiors and windows, while cleaning building exteriors (other than window cleaning and sandblasting) is classified under 561790.
4. Check the neighbors. Codes that share the first four or five digits cover related work, and several may fit your business.
5. Write down every code that fits, then narrow the list with the steps below.

Why your NAICS codes matter for federal contracts

In federal contracting, NAICS codes do two jobs.

They decide whether you count as small on each contract. SBA sets a size standard for each NAICS code, either a cap on average annual receipts or on average number of employees. A contracting officer designates one NAICS code for each solicitation, generally, and your size is measured against that code's standard as of the date of your first offer that includes price. If you think the code is wrong, you can appeal it to SBA's Office of Hearings and Appeals within 10 calendar days after the solicitation (or an amendment changing the code) is issued. An APEX Accelerator can help.

They help agencies find you. Your SAM.gov registration, including your NAICS codes, feeds your profile in SBA's Small Business Search (SBS). Agencies use it to find capable small businesses.

How to choose your primary and additional NAICS codes

Start with your primary NAICS code: the one that best describes most of your business, usually where most of your revenue comes from. It should match what you're known for.

Then add additional codes for other work you can perform well today, not work you hope to do someday.

How many NAICS codes can a company have?

You can list several NAICS codes in SAM.gov and mark one as primary. SBA puts it this way: "A business will generally have a primary NAICS code, but it can also have multiple NAICS codes if it sells multiple products and services." We couldn't find an official cap, so the practical rule is to list every code that honestly describes work you can do and would bid on.

Check the NAICS code size standard for each code

Look up the size standard for each code on your list with SBA's size standards tool or the Table of Size Standards (effective March 17, 2023). Then compare it with your own numbers:

• Receipts-based standards use your average annual receipts over your last five completed fiscal years.
• Employee-based standards use your average number of employees over the last 24 months.
• Affiliates count. If another company controls yours, or you share an owner who controls both, SBA generally adds their size to yours.

If you're over the standard for a code, you can still list it, but you won't qualify as small for set-asides that use it.

Worked example: NAICS codes for a cleaning business

Example: a commercial cleaning company that cleans offices, strips and waxes floors, shampoos carpets, and occasionally pressure-washes building entrances. Here's how it might build its list:

Say the company's average annual receipts are $6 million. It's small under all five codes.

Now say it grows to $12 million. It's still small for janitorial and facilities support contracts, but it's no longer small for carpet cleaning, other building services, or landscaping set-asides. Same company, same year, different answers, because each contract's code sets the bar. That's why checking every code matters.

The janitorial code is worth the effort. On September 25, 2026, FedReady's search of SAM.gov data showed 16 open opportunities under 561720, and 13 of them were reserved for small businesses (12 set-asides and one service-disabled veteran-owned small business sole-source notice). They included custodial services at Fort Hood (HUBZone), janitorial services for the Federal Aviation Administration in Falmouth, Massachusetts (small business), and housekeeping at Fermilab (small business).

Research which codes agencies buy under

Before you finalize your list, check how agencies code the work you do. They don't always pick the code you'd expect.

• Search open opportunities by code. Filter FedReady's free search or SAM.gov Contract Opportunities by NAICS code, and read a few notices for work like yours.
• Look up past awards. USAspending.gov shows which agencies bought under a code, who won, and for how much. SAM.gov's contract award data covers the same ground; you need a free SAM.gov account to search it.
• Note the codes on work you'd bid on. If agencies keep posting your kind of work under a code you skipped, add it (if you can do that work).

What about PSC codes?

Product and Service Codes (PSCs) describe what the government is buying, while NAICS describes the seller's industry. For a cleaning company, relevant PSCs include S201 (custodial and janitorial) and S214 (carpet laying and cleaning). PSCs are optional in SAM.gov registration, but they're useful search filters. The official list is in the PSC Manual.

Common NAICS mistakes to avoid

1. Listing only one code. You'll miss set-asides posted under related codes.
2. Listing codes you can't perform. It won't win you work, and it muddies your profile for agencies doing market research.
3. A primary code that doesn't match your revenue mix. Your primary should reflect what you mostly do.
4. Assuming your primary code decides your size. Check the standard on each solicitation's code.
5. Forgetting affiliates. Their receipts or employees can push you over a size standard.
6. Using old codes. Use NAICS 2022, not SIC codes or older NAICS editions.
7. Never revisiting your list. Your business changes, and so should your codes.

How to add or change NAICS codes in SAM.gov

You can change your codes whenever you need to, and it's free:

1. Sign in to SAM.gov through Login.gov and go to your Workspace.
2. In Entity Management, find your registration and choose to update it.
3. Choose to update or renew the entire registration. A points-of-contact-only update won't let you change codes.
4. In the Assertions section, add or remove NAICS codes and mark one as primary.
5. Review the other sections, then submit.

SAM.gov refreshed these screens in 2025 and 2026, so button names may differ slightly.

Updates go through IRS and CAGE validation, which can take up to ten business days, and you can't make more changes until the update is processed. So update well before a bid deadline, not the week of. The update also renews your registration for another year. Your annual renewal is a good time to review your codes. For the full walkthrough, see how to register on SAM.gov.

Next steps

If you're still not sure your business qualifies, read who can get government contracts. Then add your codes during SAM.gov registration and use them to find government contracts that fit. For quick definitions, see the glossary entries for NAICS code, size standard, and PSC.

This guide is general information, not legal or financial advice. Rules and thresholds change, so confirm details on SAM.gov and the official agency sites linked above before you act. FedReady is an independent company and is not affiliated with any government agency.