Overview
The six-digit classification system that governs eligibility, size standards, and discoverability
Before the US government can buy from you, it must classify what you do. Before it can assess your small business status, it needs to know your industry. Before a prime contractor can identify you as a potential subcontractor, it needs a system to search by capability.
All of this depends on a six-digit number called a NAICS code - the North American Industry Classification System. Your NAICS codes are not an administrative formality. They are one of the most strategically consequential decisions you make when entering the federal market.
NAICS codes classify businesses by their primary industry activity. The system is hierarchical - broader sector codes narrow progressively to specific activity codes. Examples:
Size Standards - The SBA assigns a different small business size threshold to each NAICS code. You may qualify as a small business under one code and exceed the threshold under another. This affects your set-aside eligibility on every specific competition.
Set-Aside Eligibility - When a contract is set aside, the contracting officer designates an applicable NAICS code. Only firms registered under that code and meeting its size standard can compete. If you have not registered the right codes in SAM.gov, you are ineligible regardless of your actual capability.
Opportunity Discovery - SAM.gov and third-party pipeline intelligence tools match open solicitations to registered NAICS codes. Correct registration determines what opportunities reach your attention automatically.
Subcontractor Discoverability - Prime contractors searching for subs use NAICS codes as the primary filter in the SBA's Dynamic Small Business Search and other databases. The right codes in the right databases are what make you visible to potential partners.
PSC Codes: A Related System Worth Knowing
Product and Service Codes (PSC codes) are a separate four-character classification system used specifically for federal procurement categorization. While NAICS codes govern your SAM.gov registration and size standard determination, PSC codes appear on solicitations and award records.
When conducting market research on USASpending.gov - identifying what has been awarded in your category, at what value, by which agencies - PSC codes are the primary search filter. Understanding how your services map to both NAICS and PSC codes gives you significantly richer pipeline intelligence than most new market entrants ever develop.