Bolivia (Beni); south-eastern Paraguay and south-eastern Brazil (southern from southern Paraná, southern Sío Paulo, southern Minas Gerais and western Rio de Janeiro) south to north-eastern Argentina (Misiones, Corrientes, eastern Formosa and eastern Chaco south to eastern Córdoba and north-eastern Buenos Aires) and Uruguay.
 
Population
Estimated population is unknown (2010).
Long-tailed Reed Finch (Donacospiza albifrons) [XC21713]
by Bernabe Lopez-Lanus from RPPN Pontal da Barra - Pelotas, Rio Grande do Sul, Brazil (duet, song)
Long-tailed Reed Finch (Donacospiza albifrons) [XC470869]
by Pedro Rinaldi from Crista do Palmares, Araras, Petr\u00f3polis, Rio de Janeiro, Brazil (chamado de contato)
Subspecies
No subspecies.
Song and colour pattern suggest that this species may be closely related to Poospiza.