NAICS Codes for Government Contracts: How to Pick the Right Ones (and Why It Matters)

Your NAICS Codes Are Your License to Compete

In federal contracting, NAICS codes aren't just a classification -- they're the filter that determines which opportunities you see and which you're invisible to. Pick the wrong codes and you'll miss contracts you're perfectly qualified for. Pick too many and you'll dilute your small business eligibility.

This guide explains how NAICS codes work, how to choose the right ones, and which codes have the most federal spending.

What Are NAICS Codes?

NAICS (North American Industry Classification System) codes are 6-digit numbers that classify businesses by industry. The federal government uses them to:

Example: NAICS 541512 (Computer Systems Design Services) has a size standard of $34 million in average annual revenue. If your company is below that threshold, you qualify as a small business for contracts under that code.

How to Choose Your NAICS Codes

Rule 1: Start With What You Actually Do

Your primary NAICS code should describe your core business activity. Don't pick a code because it has more spending -- pick it because it accurately describes your work.

Rule 2: Add Secondary Codes for Adjacent Capabilities

You can (and should) register multiple NAICS codes in SAM.gov. Add codes for:

Example: An IT services firm might register:

Rule 3: Check the Size Standard for Each Code

This is critical. Each NAICS code has its own SBA size standard. You might be "small" under one code but "large" under another.

Check your size: Go to sba.gov/size-standards to verify your eligibility for each NAICS code you register.

Rule 4: Don't Register Codes You Can't Back Up

Federal contracting officers will verify your capabilities. If you register a NAICS code you've never performed work under, you'll:

Better approach: Start with 3-5 codes where you have documented experience, then expand as you build past performance.

Top NAICS Codes by Federal Spending

We analyzed federal award data on Fed-Spend to identify the NAICS codes with the highest contract volume. Here are the top 15:

IT & Professional Services

Construction & Facilities

Healthcare & Support Services

Key insight: NAICS 541512 (Computer Systems Design) has more federal spending than any other code at $68.4B. But it's also the most competitive. Niche codes like 518210 (Data Processing) or 541715 (R&D) have strong spending with fewer competitors.

NAICS Codes With the Best Small Business Opportunity

High spending doesn't always mean high opportunity for small businesses. Here are codes where small business set-asides are highest:

The sweet spot: Codes with both high total volume AND high set-aside percentages give small businesses the best odds. Facilities Support (561210) has 51% of contracts set aside for small businesses -- over half the market is reserved for you.

Common NAICS Code Mistakes

Mistake 1: Only registering one code.

Federal opportunities are tagged with specific NAICS codes. If you only register one, you're invisible for related work. Register 3-7 codes that cover your full capabilities.

Mistake 2: Registering codes where you exceed the size standard.

If your revenue exceeds the size standard for a NAICS code, you're classified as "large" for that code -- disqualifying you from small business set-asides. Verify your size for every code.

Mistake 3: Chasing high-spending codes without capability.

NAICS 541512 has $68B in spending, but if you're a consulting firm, you won't win IT system design contracts. Match codes to your actual deliverables.

Mistake 4: Ignoring PSC (Product Service Code) alignment.

NAICS codes are broad categories. PSC codes are more specific. A solicitation for "cybersecurity assessment services" under NAICS 541512 has a different PSC than "network infrastructure installation" under the same NAICS. Understand both classification systems.

Mistake 5: Not updating codes as your business evolves.

When you add new service lines or capabilities, update your SAM.gov registration. Your NAICS codes should reflect what you can do today, not what you could do three years ago.

How Fed-Spend Uses NAICS Codes

Every feature in Fed-Spend is filterable by NAICS code:

Frequently Asked Questions

What NAICS code should I use for government contracts?

Choose NAICS codes that accurately describe your primary business activities and where you have documented past performance. Register 3-7 codes in SAM.gov covering your full capabilities. Use the SBA's NAICS code search tool or search federal awards on Fed-Spend to see which codes match the work you do.

How many NAICS codes can I register in SAM.gov?

There is no limit to the number of NAICS codes you can register in SAM.gov. However, you should only register codes where you have genuine capability and can demonstrate relevant experience. Quality over quantity -- 5 well-chosen codes are better than 20 irrelevant ones.

What is the SBA size standard for my NAICS code?

Each NAICS code has its own SBA size standard, defined either by average annual revenue or number of employees. Size standards range from $9 million to $47 million in revenue, or 100 to 1,500 employees, depending on the industry. Check sba.gov/size-standards for the current standard for your specific code.

Can I bid on contracts outside my registered NAICS codes?

Technically yes for full and open competitions, but it's not recommended. For set-aside contracts, you must be registered under the solicitation's NAICS code and meet that code's size standard. Even for full and open, contracting officers prefer vendors with relevant NAICS registration.

Which NAICS codes have the most federal contract spending?

The top five NAICS codes by federal spending are: 541512 (Computer Systems Design, $68.4B), 541330 (Engineering Services, $42.7B), 541715 (R&D, $31.2B), 541611 (Management Consulting, $28.9B), and 541511 (Custom Programming, $24.2B). Search any NAICS code on Fed-Spend to see current spending data.

Find contracts in your NAICS codes. [Search by NAICS on Fed-Spend →](/search)