Analysis
NAICS 2121 is the 2022 industry group for coal mining, part of 212 (Mining (except Oil and Gas)).
It has only one more detailed code, 21211, which covers exactly the same activities; the definition, index entries and statistics are on that page.
Between 2018 and 2023 the number of establishments fell 28% and employment fell 13%. 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.
County Business Patterns counts 491 US establishments in this code in 2023, employing 42,347 people at an average annual payroll of $106,318 per employee (87th percentile of national industries). 24% of the establishments have fewer than five employees, which points to larger operations.
By establishments it ranks 2nd of the 3 codes at this level within Mining (except Oil and Gas), with 8% of them.