The North American Industry Classification System (NAICS) is the standard federal system for classifying business establishments. Each establishment is assigned a six-digit code and category title, organizing them primarily by similar production processes into five levels: sectors, subsectors, industry groups, industries, and national industries (national industries are specific to one or more of the United States, Canada, and Mexico). Codes are hierarchical: less detailed categories are derived by removing digits from the end of more detailed codes.
Example
- 23: Construction (sector)
- 236: Construction of Buildings (subsector)
- 2362: Nonresidential Building Construction (Industry Group)
- 23622: Commercial and Institutional Building Construction (industry)
- 236220: Commercial and Institutional Building Construction (national industry which in this case is identical to its parent industry)
The NAICS classification is updated every five years to better reflect economic realities. The most recent version is NAICS 2017, used for all Emsi data.
Also see http://www.bls.gov/bls/naics.htm or http://www.census.gov/eos/www/naics/