- The official, free NAICS lookup lives at census.gov/naics and searches code titles by keyword or by drilling down from the 2-digit sector.
- Every 6-digit NAICS code is a hierarchy: the first five digits are the North American standard and the sixth digit is the US-specific national industry.
- SBA size standards are keyed to the exact 6-digit code, so a sibling code can change your small-business eligibility for set-asides.
- SAM.gov requires all 6 digits, one primary code representing your largest revenue share, and only genuine secondary codes.
- NAICS is revised every five years in years ending in 2 and 7; re-run the lookup after a revision and update SAM.gov before your next bid.
The Census Bureau NAICS code lookup at census.gov is the official, free way to find the 6-digit code that classifies your business. This walkthrough shows every click: starting a keyword search, drilling the hierarchy down to your industry, and checking the code against SBA size standards before you enter it in SAM.gov.
Where exactly is the Census Bureau NAICS lookup page and how do you start a search?
The official lookup lives at census.gov/naics, which the Census Bureau maintains as the primary source for the current NAICS code set. Bookmark it. You will return to it every time you touch SAM.gov, a capability statement, or a sources sought response.
The search box and what it matches
The landing page gives you a single keyword search box. Type a plain term like "drone" or "landscaping" and the tool returns the codes that match it. If your first keyword returns nothing or too little, try a simpler synonym before assuming the code does not exist.
Choosing the right NAICS version
Above the search box sits a selector for the code set year, currently 2022 with 2017 still available. Pick 2022 unless a solicitation explicitly references an older code. SAM.gov registration and SBA size standards both assume the current set, and GovScout Pro's own NAICS code lookup follows the same convention.
How do you narrow a broad keyword result down to your specific 6-digit NAICS code?
Type something broad like "consulting" into the census.gov NAICS search and you will get dozens of codes, from management consulting to environmental remediation consulting. That is partial-keyword matching doing its job: it returns every code that fits your term, not just the ones that fit your business. If you are new to how the six digits are structured, What Is a NAICS Code and How Do I Pick Mine? explains the hierarchy before you start drilling.
When keyword search returns 50+ codes
The fix is usually a more specific term, not a different tool. "IT consulting" beats "consulting." Try the noun a contracting officer would use in a PWS: "landscaping," not "lawn services," or "medical billing," not "healthcare." Swap singular and plural forms, because the matcher treats them literally. If you still get too much, search a distinctive word from your core service instead of the industry label you use in marketing.
Searching by 2-digit sector instead
When keywords fail entirely, browse from the top. Click the 2-digit sector that covers your work, then drill subsector, industry group, and industry until you reach the 6-digit code. Each level shows the codes beneath it, so you can read your way down rather than guess keywords. This code-index approach also surfaces adjacent codes you would never have searched for, which matters when you pick secondary codes for SAM.gov.
What do the NAICS hierarchy levels (sector, subsector, industry group, industry) mean in the census.gov results?
Every 6-digit NAICS code is a hierarchy. The census.gov results show the full path, and each extra digit narrows the description until it matches what your business actually does.
Reading the digits
Take 541512, computer systems design services. The first two digits, 54, are the sector: professional, scientific, and technical services. The first three digits, 541, are the subsector: professional, scientific, and technical services. The first four digits, 5415, are the industry group: computer systems design and related services.
The first five digits, 54151, are the NAICS industry, and the sixth digit makes 541512 the national industry. The first five digits follow the North American standard shared with Canada and Mexico; the sixth is US-specific. On census.gov, the drill-down path mirrors this: sector, then subsector, then group, then code.
Why the 6th digit matters for size standards
SBA sets revenue and employee limits per code, and they can differ between two codes in the same group. The SBA table of size standards is keyed to the 6-digit code, so picking 541512 instead of a sibling code can change whether you qualify for a set-aside. This also matters when you list codes in SAM.gov or describe your work on small business contracts.
How do you verify a NAICS code matches your primary business activity for government contracting or SBA size standards?
A census.gov code only matters once it matches what you actually sell and fits SBA's size standard for that code. Verification takes two steps: confirm the code describes your revenue-producing activity, then check the dollar or employee cap attached to it.
Checking the SBA size standard for your code
Every 6-digit NAICS code carries a size standard, usually expressed in average annual receipts or employee count, set by the SBA. If your firm's average receipts exceed the cap for your primary code, you lose small-business eligibility for set-asides tied to it, even if a different code would fit. Before you commit a code to SAM.gov, look up the size standard for that exact 6-digit code and compare it against your last three to five years of average annual revenue. Receipts are averaged, so one strong year will not necessarily push you over the cap, but two or three can. A code that feels right on paper can disqualify you if your receipts run close to or over the limit. Write the size standard down next to the code in your notes, because you will need that number again when you respond to sources sought notices.
Picking primary vs secondary codes
SAM.gov asks for one primary NAICS code, the one representing the largest share of your revenue, plus secondary codes for other lines of work. Certifications like 8(a), WOSB, SDVOSB, and HUBZone evaluate eligibility against your primary code, so pick the one that reflects your main income source, not the one with the most attractive contract volume. If construction is 70% of your revenue and consulting is 30%, construction is primary regardless of which market looks bigger.
Once your codes are locked in, tools like GovScout Pro's minority-owned contracts guide help you see which set-aside opportunities match your registration so your paperwork turns into bids you can actually pursue.
When should you use the official census.gov lookup instead of naics.com or other third-party tools?
What third-party tools add
Third-party lookups are faster for keyword searches and often bundle extras. naics.com mirrors the census data and adds plain-English descriptions. GovScout Pro's free NAICS lookup is built for contracting specifically: you search by what you do and get codes that map to set-asides and past-performance categories, not just census definitions. Paid platforms fold NAICS into broader opportunity search alongside capture and bid tracking.
Where the official tool wins
The census.gov lookup is the source of record. When a contracting officer questions your code, or when SBA size standards decide whether you qualify for an SDVOSB or 8(a) set-aside, the census definition is what governs. SBA assigns a NAICS code and size standard to each solicitation, and your small business status is measured against it.
| census.gov | naics.com | GovScout Pro free lookup | |
|---|---|---|---|
| Authoritative definitions | Yes | Mirrored | Mirrored |
| Contracting context | None | Limited | Set-aside and bid context |
| Cost | Free | Free | Free |
A practical workflow: shortlist codes in GovScout Pro or naics.com, then confirm the 6-digit code and description on census.gov before entering it in SAM.gov. Where GovScout Pro falls short: it does not replace the official hierarchy drill-down, so treat census.gov as the final verification step, not the other way around.
What are common mistakes people make when looking up their NAICS code on census.gov?
Four errors show up again and again. First, copying a 5-digit code. The results page shows the full hierarchy, but SAM.gov and your capability statement need all 6 digits, so stop one level short and you have an invalid code.
Second, ignoring the version year. NAICS is revised on a cycle, most recently in 2022, and codes can be added, split, or retired between versions. If SAM.gov expects 2022 codes and you pull a 2017 code from memory, your registration can mismatch.
Third, picking a code by keyword alone. Searching "construction" returns dozens of 6-digit options; read the definition and includes/excludes notes before choosing, because the code that sounds right may not match what you actually do. For a worked example, see our construction NAICS guide.
Fourth, stacking too many codes in SAM.gov. A long list signals no focus to contracting officers. Lead with the one or two codes covering your primary revenue, then add a handful of genuine secondary codes.
How often does the Census Bureau update NAICS codes and how do you check for revisions?
NAICS is revised every five years, in years ending in 2 and 7, through a joint process run by the United States, Canada, and Mexico. The 2022 revision was the most recent, and it added, merged, and retired codes across several industries.
To check whether your code survived a revision, run the same Census Bureau NAICS code lookup you used originally and compare the 6-digit results. If your code returns no match, look at the crosswalk of 2017-to-2022 changes on the Census site to find its successor. This matters for SAM.gov and your capability statement: if you registered under a 2017 code that changed in 2022, your listing can point to a code that no longer exists. Re-run the lookup every few years, especially after a revision year, and update SAM.gov and your NAICS references before your next bid.
Frequently Asked Questions
Can I use a 5-digit NAICS code on my SAM.gov registration?
No. SAM.gov requires all 6 digits. The census.gov results page shows the full hierarchy, and stopping at the 5-digit industry level gives you an incomplete code that will not validate. Always drill down to the final digit, which represents the national industry, before entering a code anywhere in your registration or capability statement.
Does the NAICS code I pick affect whether I qualify for set-aside contracts?
Yes. SBA assigns a size standard, expressed in average annual receipts or employee count, to each 6-digit code. If your firm's revenue exceeds the cap for your primary code, you lose small-business eligibility for set-asides tied to it. Certifications like 8(a), WOSB, SDVOSB, and HUBZone also evaluate eligibility against your primary code.
How many NAICS codes can I list in SAM.gov?
SAM.gov asks for one primary code, representing your largest share of revenue, plus secondary codes for other lines of work. There is no strict cap, but a long list signals no focus to contracting officers. Lead with the one or two codes covering your main revenue, then add only genuine secondary codes.
Is the census.gov NAICS lookup free to use?
Yes. The Census Bureau maintains the lookup at census.gov as the official, free source for the current NAICS code set. It offers keyword search, a hierarchy drill-down by 2-digit sector, and version selection between 2022 and 2017. Third-party tools like naics.com and GovScout Pro's lookup are also free but mirror or repackage the same census data.
What if my business activity doesn't match any NAICS code exactly?
Pick the code whose definition, including its includes/excludes notes, comes closest to your revenue-producing activity. Read the full description on census.gov rather than choosing by keyword alone, since the code that sounds right may not fit. If nothing matches well, try browsing the hierarchy from the 2-digit sector instead of searching keywords.