Guide
NAICS code lookup for government contractors
The North American Industry Classification System (NAICS) is how the US government categorises businesses and procurement opportunities. If your NAICS codes do not match a solicitation, you usually cannot bid — even if you are perfectly capable of doing the work. Getting the codes right is one of the highest-return steps in government contracting.
How to look up a NAICS code
The official source is the US Census Bureau NAICS search site. You can search by keyword or browse the hierarchy. Start with what your company actually does, not what you wish it did. A code is valid only if your primary revenue genuinely comes from that activity.
Search by keyword. Type the service or product you deliver. Review the full code description, not just the title.
Read the description. Two codes can have similar titles but very different scopes. The description tells you what is included and excluded.
Check size standards. The SBA assigns size standards to each code. Your small-business status depends on the code and your revenue or employee count.
Common NAICS codes for government contractors
541511 — Custom Computer Programming Services
541512 — Computer Systems Design Services
541519 — Other Computer Related Services
541330 — Engineering Services
541613 — Marketing Consulting Services
561621 — Security Systems Services
238210 — Electrical Contractors
Pick the codes that describe your core revenue. Most companies list three to five in SAM.gov.
Why NAICS codes matter for set-asides
Many solicitations are set aside for small businesses. Whether you qualify depends on the NAICS code assigned to the contract and the SBA size standard for that code. A contract coded as 541511 may have a different size limit than one coded as 541512, even if the work looks similar.
NAICS codes in SAM.gov and your capability statement
List your primary and secondary NAICS codes in SAM.gov exactly as they appear in the official lookup. Repeat them on your capability statement. When you respond to a sources-sought notice, quote the solicitation's NAICS code back to the buyer and explain why your experience maps to it.
Let the radar filter by code
Bidly stores your NAICS codes as part of your company profile and filters every SAM.gov, Grants.gov and TED notice against them. You see only the opportunities whose classification matches what you are registered to do.
Always verify the solicitation's NAICS codes and size standard on the original notice at SAM.gov before bidding.