NAICS Code Lookup Guide 2025: Find the Right Codes for Your Business
Learn how to find and select the right NAICS codes for government contracting. Understand size standards, primary vs secondary codes, and common codes by industry.
What is a NAICS Code?
A NAICS (North American Industry Classification System) code is a 6-digit number that classifies your business by industry. Government agencies use NAICS codes to find contractors and determine small business eligibility. Each NAICS code has a size standard— if your business is under that threshold, you qualify as small for set-aside contracts.
Why NAICS Codes Matter for Government Contracting
For Finding Contracts
- →Government buyers search by NAICS code
- →Contracts are advertised with required NAICS
- →Set-aside eligibility tied to specific codes
For Small Business Status
- →Each NAICS has its own size standard
- →You can be "small" for one code, "large" for another
- →Size determines set-aside eligibility
How to Find Your NAICS Code
Method 1: NAICS Association Search
- 1Go to naics.com/search
- 2Enter keywords describing your products/services
- 3Review matching codes and their descriptions
- 4Select the code(s) that best match your primary work
Method 2: Census Bureau NAICS Search
- 1Visit census.gov/naics
- 2Use the official NAICS lookup tool
- 3Browse by industry sector or search by keyword
Method 3: Check Similar Contracts
Search for contracts similar to what you want to bid on and note the NAICS codes used.
- 1. Go to SAM.gov Contract Opportunities
- 2. Search for your industry keywords
- 3. Review awarded contracts in your field
- 4. Note which NAICS codes are commonly used
Common NAICS Codes by Industry
| Industry | NAICS Code | Size Standard |
|---|---|---|
| Construction | ||
| Commercial Building | 236220 | $45 million |
| Electrical Contractors | 238210 | $19 million |
| Plumbing & HVAC | 238220 | $19 million |
| Services | ||
| Janitorial Services | 561720 | $22 million |
| Landscaping Services | 561730 | $9.5 million |
| Security Guards | 561612 | $25 million |
| IT & Professional | ||
| Custom Software | 541511 | $34 million |
| Computer Systems Design | 541512 | $34 million |
| Engineering Services | 541330 | $25.5 million |
Size Standards Explained
Each NAICS code has a "size standard" that determines if you qualify as a small business for that industry. Size is measured by either annual revenue or employee count.
Revenue-Based Standards
Most service industries use annual receipts:
- • Average annual receipts over 5 years
- • Typically $8M - $47M depending on industry
- • Include all affiliates in calculation
Employee-Based Standards
Manufacturing typically uses employee count:
- • Average employees over 12 months
- • Usually 500 or 1,000 employees
- • Include affiliates in calculation
Check Size Standards
Look up exact size standards at sba.gov/size-standards or in the SBA's Size Standards Table. These change periodically, so verify before bidding on set-aside contracts.
Using Multiple NAICS Codes
Most businesses should register with multiple NAICS codes in SAM.gov to maximize opportunities.
Primary vs. Secondary Codes
Primary NAICS
Your main line of business—the work that generates the most revenue. This is used for overall small business size determination.
Secondary NAICS
Other services you offer. Add all relevant codes to appear in more searches and bid on more contract types. No limit on secondary codes.
Important Note
When you bid on a specific contract, your size status is determined by that contract's NAICS code—not your primary code. You might be small for one contract and not small for another, depending on the assigned NAICS.
Frequently Asked Questions
Can I bid on contracts outside my NAICS codes?
Yes—your SAM.gov NAICS codes don't legally restrict what you can bid on. However, for set-aside contracts, you must be small under that contract's NAICS code. Having the matching NAICS also helps buyers find you.
How many NAICS codes should I have?
List 5-10 codes that accurately describe your services. Don't add codes for work you can't actually perform. Quality over quantity—government buyers may research your capability for each code you list.
What if no NAICS code perfectly fits my business?
Choose the closest matching codes. Many businesses fall between codes or offer unique services. Pick codes that potential government buyers would search for to find your type of work.
Are NAICS codes the same as PSC codes?
No—Product Service Codes (PSCs) are a separate federal classification system. NAICS classifies businesses by industry; PSCs classify what's being purchased. Federal contracts list both. You should know both your NAICS and relevant PSCs.
Can I change my NAICS codes later?
Yes—you can update NAICS codes in SAM.gov at any time during your annual renewal or between renewals. Review and update your codes as your business evolves.
Find Contracts Matching Your NAICS
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