NAICS Code Finder Guide

The North American Industry Classification System (NAICS) is the standard used by federal statistical agencies to classify business establishments. In government contracting, NAICS codes serve a dual purpose: they categorize the type of work being procured, and they determine the small business size standard that applies to a given contract.

Every federal contract is assigned a NAICS code by the contracting officer. To bid on that contract as a small business, your company must be 'small' under the size standard associated with that NAICS code. Size standards vary by industry and are measured either by annual revenue (typically $8 million to $47 million) or number of employees (typically 100 to 1,500).

Choosing the right NAICS codes for your SAM.gov registration is critical. Your primary NAICS code determines your default size standard, and the codes you list affect which contract opportunities you'll find when searching. You can list multiple NAICS codes, but each should genuinely represent work your company performs.

NAICS codes are 6-digit numbers organized in a hierarchical structure. The first two digits represent the economic sector (e.g., 54 = Professional, Scientific, and Technical Services). The third digit represents the subsector. The fourth digit represents the industry group. The fifth digit represents the NAICS industry. The sixth digit represents the national industry.

For example, code 541512 breaks down as: 54 (Professional Services) → 541 (Professional, Scientific, and Technical Services) → 5415 (Computer Systems Design) → 54151 (Computer Systems Design and Related Services) → 541512 (Computer Systems Design Services).

When searching for contracts, you can search at different levels of specificity. Searching at the 4-digit level casts a wider net, while the full 6-digit code is more precise. Understanding this hierarchy helps you identify related codes you might have overlooked.

Certain NAICS codes dominate federal procurement spending. Here are the most commonly used codes across major categories:

Start at the Census Bureau's NAICS search tool (census.gov/naics) and search by keyword for your business activities. Review the detailed descriptions for each code to ensure alignment with what your company actually does.

Look at what codes your competitors use. Search SAM.gov for businesses similar to yours and note their NAICS codes. Also review recent contract awards in your industry — the NAICS code assigned to each contract tells you what code contracting officers associate with that type of work.

Consider using Bidlync's contract search to see which NAICS codes appear most frequently for the types of contracts you want to pursue. This reverse-engineering approach ensures you're registered under codes that match actual procurement activity.

Don't over-list NAICS codes. While you can register under multiple codes, listing codes for work you don't actually perform can create problems during proposal evaluation. Focus on 3-8 codes that genuinely represent your capabilities.

Each NAICS code has an associated size standard that determines whether your business qualifies as 'small' for contracts under that code. Size standards are set by the SBA and are reviewed periodically.

Size standards are measured in one of two ways: annual average revenue (calculated over the most recent 5 fiscal years) or number of employees (calculated as an average over the most recent 24 months). Most service industries use revenue-based standards, while most manufacturing industries use employee-based standards.

For example, NAICS 541512 (Computer Systems Design) has a size standard of $34 million in annual revenue. If your company's 5-year average revenue is under $34 million, you qualify as small for contracts under this code. But NAICS 541330 (Engineering Services) has a size standard of $25.5 million — so the same company might be small under one code but not another.

Your primary NAICS code in SAM.gov determines your default size standard, but each individual contract is evaluated under the NAICS code assigned to that specific contract. This means you could be 'small' for some contracts and 'other than small' for others, depending on the NAICS code used.