Often considered a subspecies of Yellow-breasted Brush-finch (Atlapetes latinuchus), and both were originally considered part of a wider complex that included also Black-faced Brush-finch (Atlapetes melanolaemus) and Bolivian Brush-finch (Atlapetes rufinucha), although recent studies suggest that various components of this group may not be each other's closest relatives. Present species likely most closely related to Black-faced Brush-finch (Atlapetes melanolaemus).
BirdLife International Species Factsheet