How to Choose NAICS Codes for Government Contracting (and Why Your Size Standard Changes Every Bid)
Most owners think the NAICS code they pick in SAM.gov decides whether they count as a small business. It does not. On every solicitation, the contracting officer picks one code, that code carries its own size standard, and that is the only number that decides whether you can bid as small. Your codes decide who finds you. The buyer’s code decides whether you qualify.
That one distinction clears up most of the confusion around NAICS codes and size standards. It also explains the two mistakes we see most often: owners who list forty codes hoping to be found everywhere, and owners who certify as small on a bid without ever checking the size standard printed in that solicitation. Here is how the system actually works, how to choose your codes, and how to check your size before you sign a certification.
What a NAICS code is, in plain terms
NAICS, the North American Industry Classification System, is a list of six-digit codes the Census Bureau uses to sort businesses by what they do. It is revised every five years. It was built for economic statistics, not for contracting, which is why some codes feel oddly broad and others oddly narrow.
Government contracting borrowed it for two jobs. First, buyers search for vendors by code. When a contracting officer does market research in SBA’s Small Business Search, the codes in your SAM.gov registration are what put you in the results. Second, SBA attaches a size standard to every code, and that size standard is the line between “small” and “other than small” for that kind of work.
Size standards: the part everyone gets wrong
A size standard is either a cap on average annual receipts or a cap on employees, depending on the industry. Most manufacturing codes use employees. Most service codes use receipts. The caps vary a lot from one code to the next, which is the whole point: a firm can be small under one code and too big under another, on the same day, with the same books.
Two details catch people. Receipts are averaged over your latest five completed fiscal years, not last year’s number. Employees are averaged across every pay period in the last 24 months, and part-time and temporary staff count. And in both cases you add in your affiliates, meaning any business that controls you or that you control, or that shares common ownership. Owners with a second company are the ones most often surprised by that last rule.
SBA publishes the full table of size standards and a free Size Standards Tool that will tell you, code by code, whether you come in under the line. Use it. Do not trust a number someone quoted you on a webinar; the table gets adjusted, and the one that applies to a given bid is the one in effect when that solicitation was issued.
The contracting officer picks the code that counts
Under SBA’s rules, the contracting officer designates one NAICS code for each solicitation, the one that best describes the principal purpose of what is being bought. Outside of some multiple-award contracts, a solicitation carries one code and one size standard. That is the size standard you are measured against, and nothing in your SAM profile overrides it.
Your size is determined as of the date you certify as small with your initial offer that includes price. Not the date you registered, not the date of award. So the check has to happen per bid: open the solicitation, find the NAICS code and size standard (usually near the front, or in the set-aside clause), and compare it to your own five-year average or 24-month headcount. If you are over, you cannot bid on a small business set-aside under that code, however small you feel.
This is not a box to tick loosely. A false size certification is treated as misrepresentation under SBA’s rules, and the penalties run from losing the contract to debarment and beyond. If you are close to the line, get the math checked before you sign.
One more thing worth knowing: if you think the contracting officer chose the wrong code, and the wrong code shuts you out, the designation can be appealed to SBA’s Office of Hearings and Appeals. The window is short, about 10 days from the solicitation being issued, so this only works if you read solicitations the day they post.
How to choose your own codes
Your codes in SAM.gov are about being found and about being eligible to be found. Here is the approach we use.
Start from what buyers buy, not from how you describe yourself. Go to SAM.gov’s contract opportunities and the award data on USASpending, and look up past awards for work like yours. Note which NAICS codes the buyers actually used. That is the vocabulary you need to match. A firm that calls itself a “facilities solutions provider” might find agencies buy its work as janitorial services, landscaping services or building maintenance, three different codes with three different size standards.
Make your primary code the work most of your revenue comes from. It is the code that describes you first. Do not choose it because it has a generous size standard; choose it because it is true.
Add secondary codes only for work you would actually bid on and could actually deliver. There is no prize for volume. A long list of loosely related codes puts you in front of buyers for work you cannot do, and a contracting officer who calls you about it and gets a vague answer will remember. For most small businesses, a handful of codes is plenty.
Check your size under each one. Run every code you plan to list through the Size Standards Tool. If you are small under some and not others, that is normal. Just know which is which before a set-aside lands in your inbox.
Keep everything matching. The codes in SAM.gov, on your capability statement and in your Small Business Search profile should be the same list. Buyers notice when they are not.
What happens when you grow
Growing past a size standard is a good problem, but plan for it. Once you win a contract as small, you generally keep that status for the life of that contract, though some longer contracts and some ownership changes trigger a recertification. What changes is the next bid: if your five-year average has crossed the line under a code, you compete full and open there from now on. Owners who are near a threshold should know which of their codes will tip first, and sometimes that changes which work they chase over the next two years.
Where we come in
You can do all of this yourself. The tools are free and the rules are public. What owners pay for is getting it right the first time, because NAICS choices made by guesswork follow you into every registration, every capability statement and every certification you sign.
Our SAM.gov registration service is $597. It takes you from entity validation through active status, including NAICS and PSC selection matched to what you actually sell and the representations and certifications section. Renewal is $297 a year. Once the codes are right, bid monitoring watches new solicitations under them and sends you the ones worth a look, for $297 a month.
This is probably not a fit if…
You are already registered and your codes are right. If buyers find you and your size checks out, leave your registration alone and spend the money elsewhere.
You do one clearly defined thing. A firm that only does commercial roofing or only does translation often has an obvious code. Look it up, run the Size Standards Tool, and you are done in an afternoon.
You want someone to find you a code with a bigger size standard. We will not pick a code for its size limit when it does not describe your work. Neither should anyone else.
You have an APEX Accelerator nearby with time for you. They help with registration and code selection at no cost, and for many small businesses that is the right first stop.
Not sure whether you are ready to bid at all? The free Bid Readiness Check is five questions, and everyone who finishes it can book a free 30-minute call.
Want your registration and codes done right the first time? SAM.gov registration is $597, including NAICS and PSC selection, with renewal at $297 a year.