← Blog · April 1, 2026

NAICS Code Guide for Government Contractors: Find Your Code & Win More Bids

If you've spent any time on SAM.gov, you've seen NAICS codes everywhere. They're on every contract opportunity, every vendor profile, every size standard determination. Yet most small business owners treat them as an afterthought — picking one or two codes during SAM registration and never thinking about them again.

That's a mistake. Your NAICS codes are one of the most important factors in whether you find the right government contracts — or miss them entirely.

This guide explains what NAICS codes are, how to choose the right ones for your business, and how to use them strategically to find more contract opportunities.

What Are NAICS Codes?

NAICS stands for North American Industry Classification System. It's a standardized system used by the United States, Canada, and Mexico to classify business establishments by their primary type of economic activity.

Every NAICS code is a six-digit number. The structure works like this:

• First two digits: The economic sector (e.g., 54 = Professional, Scientific, and Technical Services)
• Third digit: The subsector (e.g., 541 = Professional, Scientific, and Technical Services)
• Fourth digit: The industry group (e.g., 5415 = Computer Systems Design and Related Services)
• Fifth digit: The NAICS industry (e.g., 54151 = Computer Systems Design and Related Services)
• Sixth digit: The national industry (e.g., 541512 = Computer Systems Design Services)

The more digits you add, the more specific the classification becomes. For government contracting, you'll almost always work with the full six-digit code.

Why NAICS Codes Matter for Government Contractors

NAICS codes serve three critical functions in federal contracting:

1. They Determine Your Size Standard

The Small Business Administration (SBA) assigns a size standard to each NAICS code. This is the threshold that determines whether your company qualifies as a "small business" for contracts under that code.

Size standards vary dramatically by industry:

A company with $25 million in annual revenue might be "small" under one NAICS code and "other than small" under another. This matters because many of the most accessible government contracts are set aside for small businesses — and your size status under the specific NAICS code assigned to the contract determines your eligibility.

2. They Control Which Contracts You See

When contracting officers post opportunities on SAM.gov, they assign a NAICS code to each one. When you search for contracts — whether on SAM.gov or a platform like GovLens — filtering by NAICS code is the single most efficient way to surface relevant opportunities.

If you're registered under the wrong codes, or missing codes that describe work you actually do, you will miss contracts that should have been on your radar.

3. They Affect Set-Aside Eligibility

Set-aside contracts (8(a), HUBZone, SDVOSB, WOSB) use the NAICS code's size standard to determine eligibility. If a contract is set aside for small businesses under NAICS 541512, you must meet the $34 million revenue threshold for that specific code — not a different code you might also be registered under.

How to Choose the Right NAICS Codes

Choosing the right NAICS codes requires thinking about both what your business does today and what contracts you want to compete for.

Step 1: Identify Your Core Services

Start with what your business actually delivers. Be specific. "IT services" is too broad — do you do custom software development (541511), systems integration (541512), data processing (518210), or IT staffing (561320)?

List out every distinct service line your company offers. Each one likely maps to a different NAICS code.

Step 2: Look at What Your Competitors Use

One of the most practical ways to find the right NAICS codes is to look at companies similar to yours that are already winning government contracts. Search USASpending.gov for competitors in your space and note which NAICS codes appear on their awards.

If a company with similar capabilities is winning contracts under a NAICS code you haven't registered for, that's a signal you may be missing opportunities.

Step 3: Check the Size Standards

Before registering for a NAICS code, verify the size standard. You need to confirm that your company qualifies as small under each code you register for — if you plan to pursue small business set-asides under that code.

The SBA's size standards table is the authoritative source. It's updated periodically, so check the current thresholds rather than relying on older references.

Step 4: Register Broadly, But Accurately

A common mistake is registering for only one or two NAICS codes. If your business does software development, cybersecurity consulting, and IT project management, you should be registered under all three relevant codes — not just the one that seems most important.

That said, don't register for codes that don't genuinely describe your capabilities. Contracting officers can and do check, and misrepresentation can have serious consequences.

Step 5: Review and Update Annually

Your SAM.gov registration requires annual renewal, and that's a natural time to review your NAICS codes. As your business evolves — adding new service lines, entering new markets, or growing past size thresholds — your NAICS code profile should evolve too.

Common NAICS Code Mistakes

Registering too narrowly. If you only register under 541512 (Computer Systems Design) but also do 541511 (Custom Programming), you're invisible to contracting officers searching for programming services.

Ignoring size standard implications. Registering under a NAICS code where you exceed the size standard means you cannot compete for small business set-asides under that code. This doesn't mean you shouldn't register — you can still compete for full-and-open contracts — but you need to know which set-asides you're actually eligible for.

Using outdated codes. NAICS codes are revised every five years (the most recent revision was 2022). Codes get added, removed, and reclassified. Make sure the codes in your SAM.gov profile are current.

Confusing NAICS with PSC codes. Product and Service Codes (PSC) are a separate classification system used by the federal government. While NAICS describes what your business does, PSC codes describe what the government is buying. Both matter, but they're not interchangeable.

Using NAICS Codes to Find Contracts Faster

Once you have the right NAICS codes, use them as your primary search filter when looking for opportunities.

On SAM.gov

SAM.gov's Contract Opportunities search allows you to filter by NAICS code. Enter your six-digit code, and the results will show only opportunities classified under that code. You can save searches and receive email notifications, though SAM.gov's notification system is basic.

On GovLens

GovLens is built around NAICS-based search. Enter your codes, add set-aside filters if applicable, and the platform returns matched opportunities with AI-generated summaries so you can quickly evaluate each one. You can save these filtered searches and receive daily email digests of new matches.

The advantage of NAICS-based search on a platform like GovLens is speed: instead of reading through dozens of SAM.gov listings to determine relevance, you get pre-filtered, summarized results that let you focus on opportunities worth pursuing.

Combining NAICS with Other Filters

NAICS codes work best when combined with other search parameters:

• Set-aside type: If you're 8(a) certified, filter for 8(a) set-asides under your NAICS codes
• Agency: If you have past performance with a specific agency, prioritize their opportunities
• Contract value: Focus on the dollar range that matches your capabilities
• Geography: Some contracts specify place of performance

The more precisely you can filter, the less time you spend evaluating irrelevant opportunities — and the more time you spend writing competitive proposals.

NAICS Codes for the Most Active Government Contracting Industries

If you're wondering where the volume is, here are some of the most frequently used NAICS codes in federal contracting:

These industries account for billions in annual federal spending. If your business operates in any of these areas, proper NAICS classification is essential.

Next Steps

1. Audit your current SAM.gov registration. Are all your NAICS codes accurate and complete?
2. Research competitors' codes. Search USASpending.gov for companies like yours and note their NAICS codes.
3. Check your size standards. Verify you qualify as small under each code where you plan to pursue set-asides.
4. Set up NAICS-filtered searches. Whether on SAM.gov or GovLens, create saved searches for each of your primary NAICS codes.
5. Review quarterly. As agencies post new opportunities and your business evolves, keep your NAICS strategy current.

Your NAICS codes are not just a registration requirement — they're a targeting system. The more precisely you define what your business does, the more precisely you can find the contracts that match.

GovLens makes NAICS-based contract search fast and automatic. Sign up free to start finding matched opportunities today.