It is found in Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and Venezuela.

[5] The mountain elaenia's specific epithet celebrates the German physician and naturalist Alexander von Frantzius, who collected the type specimen.

The subspecies are found thus:[3][7][8][9][10][excessive citations] Older field guides and other publications do not include Chiapas in the mountain elaenia's range; the species was not confirmed there until 2016.

[11] Similarly, earlier range maps do not extend to central Panama, where there are records starting in the mid 2010s.

In South America the species primarily inhabits open woodlands, scrublands, and pastures with scattered trees, and some coffee plantations and cloudforest in Colombia.

[7][8][9][10][12][excessive citations] The mountain elaenia is believed to be resident in northern Central America but appears to be an elevational migrant in Costa Rica, Colombia, and Venezuela.

It finds food mostly by gleaning while perched, while briefly hovering, and with short sallies to take insect prey on the ground.

It usually forages singly but may share a fruiting tree with numbers of its and other species, and sometimes briefly joins mixed-species feeding flocks.

Its nest is an open cup made of twigs with moss and lichen on the outside and a lining of rootlets and fungal rhizomorphs.

The northern and southern pairs of subspecies of the mountain elaenia have somewhat different vocalizations, which is part of the evidence hinting that they are separate species.

[8][9][10] "Due to its preference for open woodlands, the Mountain Elaenia tolerates some degree of urbanization and occurs in suburban habitats.