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) [XC30352]
by Eduardo Patrial from Laguna Blanca, Dep. San Pedro, Paraguay (song)
Long-tailed Reed Finch (Donacospiza albifrons) [XC103006]
by Dan Lane from Banhado do Ma\u00e7arico, Rio Grande, Rio Grande do Sul, Brazil (duet, song)
Subspecies
No subspecies.
Song and colour pattern suggest that this species may be closely related to Poospiza.