NAICS Code Finder Worksheet (Free, with Common-Codes Table)
A NAICS (North American Industry Classification System) code is a six-digit number that describes what your business does. In federal contracting it does three jobs: contracting officers assign one to every solicitation, the SBA attaches a size standard to it that decides whether you count as "small", and SAM.gov searches are filtered by it. Choosing the wrong codes means the right solicitations never reach you. This worksheet walks the four-step method, gives you a table of common codes, and shows where the codes need to appear. Free printable Word version below — just tell us where to send it.
⬇ Download the NAICS worksheet (Word)
How the code is built
- Digits 1–2: sector (23 = Construction, 54 = Professional, Scientific and Technical Services, 56 = Administrative and Support Services, 48–49 = Transportation and Warehousing, 33 = Manufacturing).
- Digit 3: subsector; digit 4: industry group; digit 5: industry; digit 6: national industry — the level federal buyers use.
- The current edition is NAICS 2022; codes are revised every five years and some are renumbered, so verify old codes against the current list at census.gov/naics.
- You do not "apply" for a NAICS code. You self-select the codes that describe your work and list them in SAM.gov; a contracting officer picks one code per solicitation.
Four steps to your codes
- Describe what you actually sell in one sentence per service line, in the customer's words (for example "install and maintain commercial HVAC systems" rather than "mechanical solutions"). Write them below.
- Search each line at census.gov/naics (keyword search) and read the full description and the "illustrative examples" — pick the code whose description matches the work you perform, not the industry you sell into.
- Check the size standard for each candidate code in the SBA table of size standards (13 CFR 121.201, published at sba.gov/size-standards). Each code has a threshold in average annual receipts or number of employees; you must be at or under it to bid as a small business under that code.
- Validate against real solicitations: search SAM.gov Contract Opportunities by each code and read five recent awards or solicitations. If the work looks like yours, keep the code. If it does not, you have the wrong code even if the words matched.
Your codes
| Service line 1 (one sentence) | |
| Candidate NAICS — description — size standard — under it? (Y/N) | |
| Service line 2 | |
| Candidate NAICS — description — size standard — under it? | |
| Service line 3 | |
| Candidate NAICS — description — size standard — under it? | |
| Primary NAICS (the one that best describes the majority of your revenue) | |
| Secondary NAICS codes (list all that apply — there is no penalty for several) | |
| Related PSC / FSC codes (Product Service Codes — the second filter buyers use; search at sam.gov/content/psc) |
Common codes for small federal contractors (verify the size standard for each — thresholds change)
| NAICS | Title | Typical work |
|---|---|---|
| 236220 | Commercial and Institutional Building Construction | General contracting on non-residential buildings |
| 238210 | Electrical Contractors and Other Wiring Installation Contractors | Electrical, low-voltage, controls |
| 238220 | Plumbing, Heating, and Air-Conditioning Contractors | HVAC, plumbing, mechanical |
| 238160 | Roofing Contractors | Roof installation and repair |
| 237310 | Highway, Street, and Bridge Construction | Paving, roadwork |
| 541330 | Engineering Services | Engineering design and consulting |
| 541511 | Custom Computer Programming Services | Software development |
| 541512 | Computer Systems Design Services | IT systems integration, network design |
| 541519 | Other Computer Related Services | IT support not elsewhere classified |
| 541611 | Administrative Management and General Management Consulting Services | Management consulting, program support |
| 541612 | Human Resources Consulting Services | HR and staffing consulting |
| 541613 | Marketing Consulting Services | Marketing, communications |
| 541690 | Other Scientific and Technical Consulting Services | Technical consulting, environmental, safety |
| 541990 | All Other Professional, Scientific, and Technical Services | Catch-all professional services |
| 561110 | Office Administrative Services | Administrative support |
| 561210 | Facilities Support Services | Facilities operations and maintenance |
| 561612 | Security Guards and Patrol Services | Guard services |
| 561720 | Janitorial Services | Custodial |
| 561730 | Landscaping Services | Grounds maintenance |
| 611430 | Professional and Management Development Training | Training delivery |
| 484121 | General Freight Trucking, Long-Distance, Truckload | Trucking |
| 811310 | Commercial and Industrial Machinery and Equipment Repair and Maintenance | Equipment repair |
| 339112 | Surgical and Medical Instrument Manufacturing | Medical device manufacturing |
| 423430 | Computer and Computer Peripheral Equipment and Software Merchant Wholesalers | IT hardware resale |
Where your codes must appear
- SAM.gov entity registration — primary and all secondary codes; this is where size representations attach.
- SBA certifications (8(a), HUBZone, WOSB, SDVOSB) — the codes on the certification profile.
- Capability statement — codes near the top, with descriptions (see the capability statement template).
- SAM.gov saved searches and BidWatch watchlist — the codes plus keywords, so solicitations reach you (saved-search setup sheet).
- GSA and agency vendor portals if you use them.
⚠️ Size is measured per code, per solicitation. You may be small under one code and other-than-small under another. Misrepresenting size on a set-aside bid is a serious matter — check the threshold for the code on each solicitation, and recheck annually as your receipts change.
Free: BidWatch watches SAM.gov for your NAICS codes and alerts you to every response deadline and amendment. Watch your first solicitation free →
Never miss the solicitation — or the amendment that changes it
BidWatch monitors SAM.gov for your NAICS codes and keywords, tracks every response deadline and amendment, and drafts your response outline. The free tier covers your first solicitation.
Start free — no card requiredGeneral guidance for small businesses entering federal contracting, not legal or contracting advice. Registration procedures, thresholds and program rules change — verify current requirements on SAM.gov, SBA.gov, Acquisition.gov (FAR) and in each solicitation. BidWatch is not affiliated with the U.S. government.