NAICS code: North American Industry Classification System.

The North American Industry Classification System (NAICS) is the standard used by US federal statistical agencies to classify business establishments for the purpose of collecting, analysing, and publishing statistical data on the US economy. It was developed jointly by the United States, Mexico, and Canada and replaced the Standard Industrial Classification (SIC) system in 1997. NAICS is reviewed and updated every five years, with the current edition being NAICS 2022. Codes are six digits, with the first two digits identifying the economic sector and successive digits adding subsector, industry group, NAICS industry, and national-industry detail.

For US federal procurement, the NAICS code is a required field on SAM.gov entity registrations and on solicitation responses. Each federal solicitation specifies a primary NAICS code, and the solicitation's small-business set-aside status, size standard, and bidder-eligibility rules flow from that designation. The Small Business Administration publishes size standards keyed to NAICS code; depending on the code, the standard is expressed as a maximum number of employees or as a maximum average annual receipts threshold. A firm above the threshold for a given NAICS code is treated as other-than-small for that code, even if it qualifies as small under a different code.

Foreign-headquartered firms entering the US federal market typically register through a US subsidiary or US-incorporated affiliate. The NAICS codes selected reflect the primary US activity of the registering entity, not the parent's home-market activity. SBA size standards apply to the entity and its affiliates on a worldwide basis, so foreign-parent affiliates count toward the size determination. Firms can register multiple NAICS codes and identify a primary code; contracting officers evaluate eligibility against the solicitation's specified code.