Coastal mountains along Minas Geraisâ€"Rio de Janeiro border, and highlands from eastern Sío Paulo and Paraná south to north-eastern Rio Grande do Sul, in south-eastern Brazil.
 
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is unknown (2010).
Bay-chested Warbling Finch (Castanozoster thoracicus) [XC677779]
by id from Itamonte, Minas Gerais, Brazil (call)
Bay-chested Warbling Finch (Castanozoster thoracicus) [XC228555]
by JAYRSON ARAUJO DE OLIVEIRA from Algulhas Negras road, Rio de Janeiro, Brazil (call)
Subspecies
No subspecies.
New molecular data indicate that genus forms a clade with the tanager (Thraupidae) genera Hemispingus and Thlypopsis, and that Compsospiza, which often subsumed within present genus, is sister to that clade.