Analysis
NAICS 4595 is the 2022 industry group for used merchandise retailers, part of 459 (Sporting Goods, Hobby, Musical Instrument, Book, and Miscellaneous Retailers).
It has only one more detailed code, 459510, which covers exactly the same activities; the definition, index entries and statistics are on that page.
County Business Patterns publishes no national count for it, either because the code is out of the survey's scope or because the figures are suppressed to protect individual businesses.