Analysis
NAICS 23821 is the 2022 NAICS industry for electrical contractors and other wiring installation contractors, part of 2382 (Building Equipment Contractors).
It has only one more detailed code, 238210, which covers exactly the same activities; the definition, index entries and statistics are on that page.
County Business Patterns counts 83,342 US establishments in this code in 2023, employing 1,015,983 people at an average annual payroll of $76,545 per employee (64th percentile of national industries). 59% of the establishments have fewer than five employees, which is close to the national mix.
Between 2018 and 2023 the number of establishments grew 11% and employment rose 18%. The 2018 count used NAICS 2017, so part of a large move can come from codes being redefined rather than from businesses opening or closing.
By establishments it ranks 2nd of the 3 codes at this level within Building Equipment Contractors, with 41.1% of them.
Official definition
See industry description for 238210.
Source: US Census Bureau, NAICS 2022 Manual.