South-eastern Brazil (southern Goiás, southern Minas Gerais and Espírito Santo south to northern Rio Grande do Sul), eastern Paraguay (Canendiyu, Alto Paraná, Itapúa) and north-eastern Argentina (Misiones, Corrientes).
 
Population
Estimated population is unknown (2010).
Rufous-capped Spinetail (Synallaxis ruficapilla) [XC277689]
by Jeremy Minns from Ubatuba, SP. Folha Seca, Brazil (call)
Rufous-capped Spinetail (Synallaxis ruficapilla) [XC494559]
by Ciro Albano from PP Urugua-i, Misiones, Argentina (song)
Subspecies
No subspecies.
Forms a superspecies with Synallaxis cinerea and Pinto's Spinetail (Synallaxis infuscata), this superspecies suggested by some authors as being most closely related to Sooty-fronted Spinetail (Synallaxis frontalis), Azara's Spinetail (Synallaxis azarae) and Apurimac Spinetail (Synallaxis courseni) on basis of plumage and vocal similarities. Formerly considered to include Pinto's Spinetail (Synallaxis infuscata) as a subspecies, but vocal differences indicate that latter merits rank of full species.