[3] However, one author has treated it as a subspecies of the eared pygmy tyrant (M. auricularis)[2]; major taxonomic systems retain it as a full species.

Adults have a buff whitish area surrounding the eye with a grayish crescent behind the ear coverts.

Their throat and upper breast are whitish with faint gray streaks and the rest of their underparts are white with a tinge of yellowish olive on the sides and crissum.

[8][9] The white-bellied pygmy tyrant is found intermittently along the eastern slope of the Andes from extreme southeastern Zamora-Chinchipe Province in southern Ecuador south through Peru and central Bolivia as far as western Santa Cruz Department.

It inhabits humid montane forest, where it favors edges and gaps such as those caused by fallen trees.

It mostly forages in the vegetation's lower and middle levels, taking prey using short upward sallies from a perch to grab it from leaves.