The family was established based on the type genus Endomychus, a genus erected in 1795 by Panzer which was applied to a species that Linnaeus called Chrysomela coccinea.

They have a tarsal formal of 4-4-4 or 3-3-3 and the wings lack a closed radial cell.

[1] A 2015 molecular phylogeny study found that the Cucujoidea were found to be non-monophyletic and the Endomychidae was refined with the removal of the Anamorphinae from within the family and elevated to the status of a full family, Anamorphidae.

Mycetaeinae and Eupsilobiinae were also found not to belong within the clades of the core Endomychidae, and likewise reclassified into the families Mycetaeidae and Eupsilobiidae.

[2] The subfamilies that are included: These 70 genera belong to the family Endomychidae as defined in the past (due to revisions, this may not be entirely accurate): Data sources: i = ITIS,[3] c = Catalogue of Life,[4] g = GBIF,[5] b = Bugguide.net[6]