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) [XC737967]
by Guilherme de Barros Brand\u00e3o from Rio do Oeste, State of Santa Catarina, Brazil (song)
Grey-bellied Spinetail (Synallaxis cinerascens) [XC302129]
by Jerome Fischer from Rio Piracicaba, Minas Gerais, Brazil (alarm call, song)