Extreme south-eastern Ecuador (extreme upper Marañón drainage near Zumba, in southern Zamoraâ€"Chinchipe) and north-central Peru (middle and upper R Marañón and upper R Huallaga/R Utcubamba, in western Amazonas and Cajamarca).
 
Population
Estimated population is unknown (2010).
Buff-bellied Tanager (Thlypopsis inornata) [XC259561]
by John V. Moore from Zamora-Chinchipe: El Chorro area, SE of Zumba, Ecuador (call, calls in flight)
Buff-bellied Tanager (Thlypopsis inornata) [XC823119]
by id from La Chonta (near Pucabamba), Chinchipe, Zamora Chinchipe, Ecuador (song)