In Plain English
Quick Answer
A six-digit government code for what kind of work your business does. Construction codes start with 236, 237, or 238. Every contract is tagged with one, and it sets the small-business size limit for that job.
Definition
Definition
The North American Industry Classification System (NAICS) is the standard U.S. federal agencies use to classify businesses by their primary economic activity. Each business is assigned one or more six-digit codes; construction is Sector 23, subdivided into 236 (building construction), 237 (heavy and civil engineering construction), and 238 (specialty trade contractors). Agencies assign a NAICS code to every solicitation, and it determines the applicable SBA small-business size standard and set-aside eligibility.
Context
Why It Matters in Bidding
NAICS is the first filter in bid discovery: the code on a solicitation decides whether your firm even sees it, whether you meet the small-business size standard, and whether a set-aside applies. Estimators who register the wrong primary code miss matching opportunities and waste hours vetting bids they cannot win. Codes that mirror your actual scope keep the pipeline full of winnable work.
Example
Example
A specialty electrical sub sets NAICS 238210 as its primary code in SAM.gov, so agency bid alerts surface electrical solicitations while filtering out unrelated 236220 building-GC work.
See Also
Related Terms
FAQ
Questions Contractors Ask
Can a contractor have more than one NAICS code?
Yes. A firm registers every NAICS code that describes its work in SAM.gov and designates one primary. Each solicitation is issued under a single code, and your size eligibility is judged against that code's standard, so carrying multiple codes widens the building, heavy-civil, and specialty-trade opportunities you can pursue.
How does a solicitation's NAICS code affect small-business eligibility?
Every solicitation names one NAICS code, and the SBA size standard tied to it (a revenue or employee ceiling) decides whether you count as small for that bid. The same company can be small under a $45M building code yet large under a lower-threshold code, so the assigned code directly gates set-aside access.
Can I challenge the NAICS code on a solicitation?
Yes. A bidder who believes the contracting officer picked the wrong code can file an SBA NAICS appeal, generally within 10 calendar days of the solicitation's issuance. A successful appeal changes the applicable size standard and can reopen the bid to firms the original code excluded.
Do state and local bids use NAICS codes too?
Federal solicitations always carry a NAICS code, and many state, county, and municipal portals let you register and filter by it. Where a local agency uses its own commodity codes instead, mapping your NAICS code to those categories still helps you configure accurate bid alerts across portals.
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