What Is a NAICS Industry Code and Why It Matters for Federal Contractors

A NAICS (North American Industry Classification System) code is a 6-digit number assigned to every business that identifies what industry you operate in—used by federal procurement systems to match your firm to relevant contract opportunities. Every US business registered with the IRS has one, and federal contractors must claim the correct codes in SAM.gov to receive solicitation notices for work your firm can actually win.

Why NAICS Codes Control Which Contracts You See

When federal agencies post solicitations on SAM.gov, they specify which NAICS codes are eligible to bid. If your firm's codes don't match, the solicitation won't reach you—even if you're fully capable of performing the work.

For example, if your construction firm specializes in concrete foundations but is only registered under NAICS 238110 (Poured Concrete Foundation and Structure Contractors), you might miss opportunities posted under NAICS 236220 (Commercial and Institutional Building Construction). The government uses these codes to route work to the right pool of contractors, and you only get invited to bid if your registered codes align with what the agency is buying.

This is also why NAICS codes affect your firm's access to small business set-asides. If you hold an 8(a) certification, HUBZone status, or Women-Owned Small Business status, those designations are tied to specific NAICS codes. Claim the wrong codes, and you can't compete for reserved opportunities.

How to Find Your Business's NAICS Code

Your primary NAICS code is determined by the Census Bureau based on your IRS filings and business structure. You can look it up yourself using the Census Bureau's NAICS search tool at census.gov/naics. Type in a description of what your business does—for example, "electrical contracting" or "IT consulting"—and the tool will return matching codes with descriptions.

You can also ask your accountant or CPA; they'll have it on file from your business tax returns. If you file as a sole proprietor or LLC, your accountant assigned a NAICS code to your Schedule C or corporate return years ago.

SAM.gov also shows your current registered NAICS codes if you log into your entity account. To view them, navigate to your entity profile under "Representations and Certifications" and look for the NAICS code section. If you've never registered on SAM.gov, you'll need to create a federal account first (or have your authorized representative do so).

Registering Multiple NAICS Codes on SAM.gov

You can claim up to five NAICS codes on SAM.gov if your business operates across multiple lines of work. Many firms do this legitimately—a general contractor might claim codes for building construction, site preparation, and demolition services all under one firm.

The key is claiming codes where you actually generate revenue. If you're an IT contracting firm but you also do administrative support work, you could register both NAICS 541512 (Computer Systems Design Services) and NAICS 561110 (Office Administrative Services). Adding secondary codes expands the solicitations you'll see, but only if those codes reflect real business activity.

When you update your SAM.gov entity profile, there's a section to add, remove, or designate your primary NAICS code. Your primary code should reflect your largest revenue stream or the work that defines your firm's primary identity.

Common NAICS Codes for Government Contractors

Why Getting Your NAICS Code Right Matters Now

Misalignment between your actual business and your registered NAICS codes costs you opportunities. If an agency posts a solicitation for construction services but you're only registered under an IT services code, you won't see it. If you claim too many secondary codes that don't match your real revenue, you risk audit questions during a government contracting compliance review.

Tools like BidWatch monitor SAM.gov solicitations by NAICS code and alert you when new opportunities match your firm's registered codes. If your codes are wrong, even a monitoring system can't help you—you'll be alerted to work you shouldn't be bidding on, or you'll miss the right opportunities entirely.

Steps to Verify and Update Your NAICS Codes

1. Log into your SAM.gov entity account (or have your authorized representative do so).
2. Navigate to your entity profile and check the "Representations and Certifications" section.
3. Review your primary and secondary NAICS codes. Do they match the work you actually perform and invoice for?
4. If codes are missing or incorrect, click "Edit" and update them. You can add up to five codes total.
5. Make sure your primary code (the first one listed) reflects your largest revenue source.
6. Save and submit your changes. SAM.gov will confirm the update.
7. Check the "Last Updated" date on your entity profile. Federal agencies see this timestamp—recent updates signal your data is current.

NAICS Codes and Small Business Certifications

If you hold or are pursuing an 8(a), HUBZone, Women-Owned Small Business, or Service-Disabled Veteran-Owned Small Business certification, your NAICS codes are tied directly to your eligibility. The SBA sizes your firm based on your primary NAICS code's revenue thresholds—construction firms have different size standards than IT services firms, for example.

If you're certified under one NAICS code but you bid on contracts under a different code in that same certification program, the SBA may challenge the bid. For this reason, it's critical that your SAM.gov NAICS registration matches what you've told the SBA during your certification application.

FAQs About NAICS Codes for Federal Contractors

Can I change my NAICS code whenever I want?

You can update your NAICS codes in SAM.gov any time, and the changes take effect immediately. However, if you hold a small business certification, a significant change to your primary NAICS code might trigger an SBA review. Changes that reflect actual shifts in your business operations are fine; changes that look like you're trying to game the system for a particular contract will raise flags.

What happens if I claim a NAICS code I don't actually do work under?

If you claim a NAICS code but you don't have the personnel, equipment, or revenue history to back it up, and then you win a contract under that code, a contracting officer's post-award audit could challenge your eligibility. You could be required to return the contract value or face other consequences. Register only codes that reflect real business lines.

Do I need the exact same NAICS code to bid on a solicitation?

A solicitation will specify one or more eligible NAICS codes. You must have at least one NAICS code on file in SAM.gov that matches one of the eligible codes posted in the solicitation. If your codes don't overlap, you can't bid.

Where else are NAICS codes used?

Beyond SAM.gov, NAICS codes determine which federal reports your firm may need to file, which small business program eligibility applies to you, and how the Census Bureau classifies your business. Some federal agencies also use NAICS codes for industry diversity reporting and contract history tracking.