Andes of western Venezuela (Táchira), and locally in eastern range in Colombia, eastern Ecuador (one record from western slope) and northern Peru (south to Huánuco).
 
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is unknown (2010).
Sulphur-bellied Tyrannulet (Mecocerculus minor) [XC61398]
by Willem-Pier Vellinga from Caba\u00f1as San Isidro, Cosanga, Napo, Ecuador (call, song)
Sulphur-bellied Tyrannulet (Mecocerculus minor) [XC276163]
by Guilherme Melo from Carchi: Chilma, Ecuador (call, dawn song)
Subspecies
No subspecies.
Genus as presently constituted is probably polyphyletic, and in need of further study. Syringeal characters suggest that present species and Rufous-winged Tyrannulet (Mecocerculus calopterus) are possibly related to Phyllomyias, specifically to Tyranniscus if latter resurrected.