NAICS Codes for Government Contracting: Complete Selection Guide

Quick Overview: NAICS Codes

NAICS (North American Industry Classification System) codes are 6-digit numbers that classify businesses by industry type. In government contracting, your NAICS codes determine which opportunities you can pursue and whether you qualify as a small business for set-aside contracts worth billions annually.

1,000+

NAICS Codes

6 Digits

Code Format

23%

Small Biz Goal

$150B+

Set-Aside Spend

What are NAICS Codes?

NAICS codes are standardized classifications used by the United States, Canada, and Mexico to categorize businesses by their primary economic activity. The system replaced the older SIC (Standard Industrial Classification) codes and provides a more detailed, modern classification structure.

Code Structure

2 digits
Sector
Broadest category (e.g., 23 = Construction)
3 digits
Subsector
More specific (e.g., 236 = Construction of Buildings)
4 digits
Industry Group
Narrower focus (e.g., 2362 = Nonresidential Building)
6 digits
National Industry
Most specific (e.g., 236220 = Commercial Construction)

Example: IT Services

54Professional, Scientific, and Technical Services
541Professional, Scientific, and Technical Services
5415Computer Systems Design and Related Services
54151Computer Systems Design and Related Services
541512Computer Systems Design Services

Why NAICS Codes Matter in Government Contracting

Your NAICS codes have significant implications for your federal contracting business. They affect everything from which opportunities you see to your eligibility for set-aside programs.

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Size Determination

Each NAICS code has a size standard that determines if you qualify as a small business for that industry. Different codes have different thresholds.

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Opportunity Matching

Federal contracts are classified by NAICS code. Your registered codes determine which opportunities appear in your searches and alerts.

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Set-Aside Eligibility

Small business set-asides, 8(a), HUBZone, and other programs evaluate your size based on the NAICS code assigned to each specific contract.

Critical Point

You may qualify as a small business under one NAICS code but not another. A company with $30 million in revenue is small for construction (threshold $39.5M) but large for many professional services (threshold $19.5M).

Size Standards Explained

The SBA sets size standards for each NAICS code, measured either by average annual receipts or number of employees. Meeting the size standard makes you eligible for small business programs.

Industry Type	Measurement	Common Thresholds
Professional Services	Annual Receipts	$19.5M - $30M
Construction	Annual Receipts	$16.5M - $45M
Manufacturing	Employees	500 - 1,500
IT Services	Annual Receipts	$34M - $40M
Wholesale Trade	Employees	100 - 250

Annual Receipts Calculation

For receipt-based standards, SBA calculates a 5-year average of your annual receipts.

• Include all revenue from business operations
• Joint ventures may aggregate revenue
• Affiliates' revenue typically included
• Tax returns are the primary source

Employee Count Calculation

For employee-based standards, count all full-time, part-time, and temporary workers.

• 12-month average of all employees
• Include part-time as full employees
• Count temporary and leased workers
• Affiliates' employees may be included

Selecting the Right NAICS Codes

Choosing appropriate NAICS codes is critical for maximizing your opportunities while accurately representing your business capabilities.

Step-by-Step Selection Process

Identify Your Core Services

List all products and services your company provides. Focus on what generates the most revenue and what you want to sell to the government.

Research Matching Codes

Use the Census Bureau's NAICS search tool or SBA's size standards table to find codes that match your services. Read the full descriptions carefully.

Check Size Standards

Verify the size standard for each code. Consider whether you qualify as small business under codes that matter most to your strategy.

Review Contract History

Search SAM.gov and FPDS for contracts in your industry. See which NAICS codes agencies commonly use for services like yours.

Select Primary and Secondary Codes

Choose one primary code representing your main business activity. Add secondary codes for other significant services you offer.

Common NAICS Codes for Government Contractors

IT & Technology

541512 - Computer Systems Design Services
541511 - Custom Computer Programming
541519 - Other Computer Related Services
518210 - Data Processing & Hosting
541513 - Computer Facilities Management

Professional Services

541611 - Administrative Management Consulting
541618 - Other Management Consulting
541990 - All Other Professional Services
561110 - Office Administrative Services
541614 - Process & Logistics Consulting

Construction

236220 - Commercial Building Construction
237310 - Highway & Street Construction
238210 - Electrical Contractors
238220 - Plumbing & HVAC Contractors
237990 - Other Heavy Construction

Engineering & Research

541330 - Engineering Services
541310 - Architectural Services
541380 - Testing Laboratories
541715 - R&D in Physical Sciences
541714 - R&D in Biotechnology

NAICS Codes in SAM.gov Registration

When registering in SAM.gov, you'll select NAICS codes that represent your business capabilities. This information is used by contracting officers to find potential vendors.

SAM.gov NAICS Requirements

Primary NAICS Code

Select one code representing your main business activity. This is required.

Additional NAICS Codes

Add all codes where you have genuine capability. No strict limit, but be accurate.

Small Business Indicators

SAM shows your size status for each code based on current size standards.

Pro Tip: Keep Your Profile Updated

Review your NAICS codes annually. As your business evolves, you may need to add new codes or update your primary code. Size standards also change periodically, so verify your small business status remains accurate.

Strategic NAICS Code Considerations

Maximize Small Business Status

If you're approaching the size threshold for your primary NAICS code, consider whether opportunities under a different code with higher thresholds might be more strategic. However, never misrepresent your primary business activity.

Watch for NAICS Code Protests

Competitors can protest the NAICS code assigned to a solicitation if it doesn't match the principal purpose of the work. Understanding proper NAICS assignment helps you identify opportunities and potential protest issues.

Plan for Growth

As your company grows, you may exceed size standards. Develop a strategy for transitioning from small business to full-and-open competition, including building past performance on larger contracts.

Use BidFinds for NAICS Filtering

Set up opportunity alerts filtered by your NAICS codes to receive relevant contract notifications automatically. This ensures you don't miss opportunities in your industry.

Frequently Asked Questions

How many NAICS codes can I have?

There's no strict limit on secondary NAICS codes in SAM.gov, but you should only list codes where you have genuine capability and experience. Adding irrelevant codes won't help and may raise questions about your credibility.

Can I protest a contract's NAICS code?

Yes, you can challenge the NAICS code assigned to a solicitation if it doesn't reflect the principal purpose of the acquisition. Protests go to SBA's Office of Hearings and Appeals and must be filed before the solicitation closes.

What if my work spans multiple NAICS codes?

Many contracts involve multiple services. The contracting officer assigns the NAICS code that best describes the principal purpose of the acquisition. For bundled services, expect the code representing the largest portion of contract value.

How often do size standards change?

SBA reviews and updates size standards every 5 years, though individual industries may be adjusted more frequently. Check SBA.gov for current standards and proposed changes that might affect your small business status.

Can I be small for some contracts and large for others?

Yes. Your size status is determined by the NAICS code assigned to each specific contract. You might qualify as small for a construction contract but not for a professional services contract, depending on the respective size standards.

Find Contracts in Your NAICS Codes

BidFinds helps you discover federal contract opportunities filtered by your NAICS codes. Set up custom alerts and never miss an opportunity in your industry.

Start Finding Opportunities →View Pricing

Related Resources

SAM.gov Registration

Complete registration guide

8(a) Certification

Small business program guide

Set-Aside Programs

Small business advantages