Dramatic differences in song (Boesman 2016w) justify a split between two widely allopatric, monotypic groups; therefore the group Golden-bellied Warbler (Golden-bellied) Myiothlypis chrysogaster chrysogaster becomes Cuzco Warbler Myiothlypis chrysogaster; and the group Golden-bellied Warbler (Choco) Myiothlypis chrysogaster chlorophrys becomes Choco Warbler Myiothlypis chlorophrys. Revise the range from "E slope of Andes of Peru (Huánuco and Junín to Puno)" to "east slope of Andes of central and southern Peru (Huánuco and extreme southwestern Loreto south to Puno) and western Bolivia (La Paz)".