The rusty-bellied brushfinch (Atlapetes nationi) is a species of bird in the family Passerellidae, the New World sparrows. It is endemic to Peru.
Taxonomy and systematics
The rusty-bellied brushfinch was formally described in 1881 with the binomial Buarremon nationi. Its specific epithet honors William Nation, who provided the type specimen. Genus Buarremon was merged into Atlapetes early in the twentieth century. Various authors have treated the rusty-bellied brushfinch as conspecific with one of the slaty brushfinch (A. schistaceus) or the bay-crowned brushfinch (A. seebohmi).
The rusty-bellied brushfinch has two subspecies, the nominate A. n. nationi (Sclater, PL, 1881) and A. n. brunneiceps (Berlepsch and Stolzmann, 1906).
