Nobody hands you a NAICS code. You pick it yourself, out of a list published by the Census Bureau, and that choice follows you through every bid you submit. Get it wrong and you either miss opportunities you were qualified for, or you show up under a set-aside you do not actually meet the size standard for.
Here is how the system actually works, and how to find the codes that fit what you do.
What a NAICS code actually is
NAICS stands for North American Industry Classification System. It is a six-digit code that describes an industry, maintained jointly by the U.S., Canada, and Mexico and revised every five years. The federal government uses it to classify what a business does, which contracting officers use to decide which businesses can bid on which work.
There is no application. No certification. No office that reviews your choice. You self-select the codes that describe your business when you register in SAM.gov, and you can add or change them later.
Why the code matters more than it looks like it should
Two things ride on your NAICS code.
Size standard. Every NAICS code has a corresponding small business size standard set by the SBA, expressed in either average annual receipts or number of employees. The same company can be "small" under one code and "not small" under another, because the thresholds are set per industry, not per business.
Set-aside eligibility. A solicitation is posted under a specific NAICS code. If you are not registered under that code, or you do not qualify as small under it, you cannot compete for that set-aside, full stop.
How to find the right codes
- Search by keyword, not by guessing a number. The Census Bureau runs the official NAICS lookup tool. Type in a plain description of what you do, roofing, IT staffing, janitorial services, and it returns the matching codes.
- Read the full code description, not just the title. Codes get specific fast. "Janitorial Services" and "Landscaping Services" sit one digit apart and are not interchangeable.
- Check the size standard before you commit. Run each candidate code through the SBA's Size Standards Tool. A code with a size standard you clear is worth more to you than one you do not.
- Register more than one. Most businesses qualify under several NAICS codes, and SAM.gov lets you list all of them. Pick a primary code, the one that best represents your main business, then add the rest.
- Revisit them as your business changes. A code you picked at registration might not match what you actually bid on two years later. Nothing stops you from updating it.
What this looks like once you are bidding
The codes you register under are what a sourcing pipeline actually filters on. If your NAICS list is thin or slightly wrong, you are not seeing opportunities you would otherwise qualify for. This is one of the first things worth checking in how a daily pipeline scans and scores opportunities: the match starts at the NAICS code, before anything else about the solicitation gets read.
Your NAICS codes are not a formality you fill in once and forget. They are the filter everything else runs through.
Once your codes are dialed in, some contract vehicles are worth a second look precisely because they sit across many NAICS codes at once. Our breakdown of GSA Schedule contracts covers what a Schedule actually takes to get on, and why we tell most first-time bidders to wait.
Related reading
- How to Register on SAM.gov: A Step-by-Step Guide
- What Is a Sources Sought Notice, and Should You Respond?