NAICS (the North American Industry Classification System) is the numbering scheme the government uses to say what industry a business — or a piece of work — belongs to. Every code is six digits, reading from general to specific: the first two digits are the broad sector (23 is Construction, 54 is Professional/Technical Services, 56 includes facilities support), and each further digit narrows it. The current edition is NAICS 2022.
For most of the economy, NAICS is statistical wallpaper. For a government contractor, it's load-bearing. Here's why, and how to pick yours.
Every solicitation carries a NAICS code. When a contracting officer posts work on SAM.gov, they assign it one code that best describes the work. That single assignment drives almost everything downstream.
Size standards attach to the code. "Small business" isn't one definition — the SBA sets a size ceiling (annual revenue or employee count) per NAICS code. The same company can be small under one code and not under another. Whether you're eligible for a small business set-aside on a given contract depends on the code that solicitation carries and whether you're under its ceiling.
Your codes drive what you find. SAM.gov searches and saved-search alerts filter by NAICS. If your codes are wrong or incomplete, the right opportunities never reach your inbox — you can't bid what you never see. (Setting up those free alerts is step one for everyone; here's how.)
Set-asides flow through it. Whether work gets set aside for small business — and whether you count toward the Rule of Two when you answer market research — runs through the NAICS code and its size standard.
Your SAM.gov registration lists one primary NAICS code — the code for the work that's the core of your business — plus as many additional codes as genuinely apply.
The primary code is what shows up first when agencies and primes look you up, so it should describe what you'd want to be known for. Additional codes cost nothing to list and make you findable for adjacent work. The keyword is genuinely: each code you list is a claim that you actually perform that kind of work.
One practical note: nothing limits you to bidding only your listed codes. What matters at bid time is whether you can perform the work and whether you're small under the solicitation's code. But your listed codes are how the ecosystem — search filters, agency market research, prime contractors hunting subs — finds you.
1. Start from what you'd actually bid. Write down, in plain words, the jobs you want the government to hire you for. Not your aspirations — your crews, your licenses, your past projects. The codes should describe that list.
2. Find the matching codes. Use the NAICS search at census.gov/naics — type plain-language descriptions ("roofing contractors," "janitorial services," "computer systems design") and read the official definitions. Read the full definition, not just the title; codes that sound right sometimes cover different work than you'd guess.
3. Check the size standard for each candidate code. Use the SBA's Size Standards Tool at sba.gov. You want to know two things: that you're small under the codes you'll compete in, and how much headroom you have. If you're near a ceiling, that affects strategy.
4. Sanity-check against real solicitations. Search SAM.gov for recent notices under each candidate code. If the work posted under a code looks nothing like what you do, you've got the wrong code, whatever its title says. If you've never bid before, this is also a free education in what the government actually buys — our starter guide covers reading those notices.
5. Pick one primary, a handful of additionals. The primary is your core trade. Additionals are codes where you could credibly win work today.
Picking aspirational codes. Listing a code for work you hope to grow into — but couldn't perform if awarded tomorrow — pollutes your search results with unbiddable notices and tells anyone doing market research a small lie. List the business you have. Add codes when the capability is real.
Listing too many codes. Twenty additional codes doesn't make you findable for twenty kinds of work; it makes your profile read as unfocused, and it floods your alerts with noise you'll learn to ignore. A primary plus a focused handful beats a shotgun blast.
Never revisiting. Businesses drift. The shop that was 80% residential remodel three years ago might be 80% commercial roofing now — with a primary code still pointing at the old business. Size standards also get revised, and the NAICS edition itself updates periodically (2022 is current). Put a yearly reminder on the calendar — your SAM registration needs annual renewal anyway, so review your codes then.
Treating the code as the whole story. A solicitation's NAICS is one contracting officer's judgment call about work that often spans trades. Real opportunities for you regularly post under codes you'd never think to list — facility-support codes hiding electrical work, construction codes hiding design work.
That last mistake points at the structural limit of NAICS: it's a filing system, not a description of fit. This is why Bird Dog's capability profile takes both your NAICS codes and plain-language keywords about the work you do — and reads the full text of every notice — so a job that's really yours still surfaces even when it was filed under an adjacent code your filters would have missed. The profile takes about 60 seconds, and seeing your daily matches is free.
See what fits your shop — free, 60-second setup.
Last reviewed: 2026-06-10