Analysis
NAICS 5511 is the 2022 industry group for management of companies and enterprises, part of 551 (Management of Companies and Enterprises).
It has only one more detailed code, 55111, which covers exactly the same activities; the definition, index entries and statistics are on that page.
County Business Patterns counts 49,556 US establishments in this code in 2023, employing 3,855,720 people at an average annual payroll of $128,997 per employee (93rd percentile of national industries). 37% of the establishments have fewer than five employees, which is close to the national mix.
Between 2018 and 2023 the number of establishments fell 9% and employment rose 9%. 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.