South-eastern Brazil (southern from southern Goiás, southern Minas Gerais and southern Espírito Santo), eastern Paraguay (eastern from Paraguarí), north-eastern Argentina (Misiones, eastern Corrientes) and northern Uruguay.
 
Population
Estimated population is unknown (2010).
Grey-bellied Spinetail (Synallaxis cinerascens) [XC698134]
by Miguel Angelo Biz from RPPN Vale dos Ip\u00eas, Cl\u00e1udio, Minas Gerais, Brazil (song)
Grey-bellied Spinetail (Synallaxis cinerascens) [XC388535]
by Ricardo Gagliardi from Sales\u00f3polis, S\u00e3o Paulo, Brazil (song)