Although the Hepatic Tanager has the most restricted range of the four tanagers in the United States, in fact it is the most widespread member of its genus. It breeds from the southwestern United States southward all the way to Argentina.
The Hepatic Tanager may include three different species: the Hepatic Tanager, found from the United States southward to Nicaragua; the Tooth-billed Tanager, found from Costa Rica to northern South America; and the Red Tanager of eastern and southeastern South America. The two southern forms lack the dusky ear coverts of the northern form.
The Hepatic Tanager has been little studied. As of 2002, only 106 had been banded in the United States, and only one banded bird had ever been recovered.