South-eastern Bolivia (Cochabamba and Santa Cruz south to eastern Chuquisaca and eastern Tarija), western and central Paraguay (except extreme eastern Alto Paraná), northern and north-central Argentina (Salta, Jujuy and Formosa south to San Luis, central Cordóba and extreme northern Buenos Aires), western Uruguay and south-eastern Brazil (extreme western Rio Grande do Sul).
 
Population
Estimated population is unknown (2010).
Black-capped Warbling Finch (Microspingus melanoleucus) [XC339549]
by Dan Lane from Departamento de Paysand\u00fa, Uruguay (alarm call)
Black-capped Warbling Finch (Microspingus melanoleucus) [XC348822]
by Niels Krabbe from Florida, Santa Cruz, Bolivia (call, song, excitement chatter)
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 this genus, is sister to that clade. A recent molecular-genetic study indicated that present species belonged to a clade that included also Plain-tailed Warbling-Finch (Microspingus alticola), Rusty-browed Warbling-Finch (Microspingus erythrophrys) and Ringed Warbling-Finch (Microspingus torquatus). Until recently it was treated as conspecific with Cinereous Warbling-Finch (Microspingus cinereus).