The mountain chickadee was formerly placed in the genus Parus with most other tits, but mtDNA cytochrome b sequence data and morphology suggest that separating Poecile more adequately expresses these birds' relationships.

Inside of the nest, the female mountain chickadee builds a seal for entry from resources she gathers, such as fur.

Mountain chickadee populations are often limited to certain locations which have good nesting sites and many cavities for inhabiting.

They cling to the undersides of branches and to tree trunks, searching for food in the bark or breaking seeds open by hammering them with their beaks.

Due to their insect-rich diet, Mountain Chickadees help to manage and control insect populations.

[11] They travel in pairs or small groups, and may join multi-species feeding flocks after breeding season.

This makes the mountain chickadee's callings and songs a very important factor in their reproduction.

[14] Individuals in urban areas appear to be able to habituate quickly to novel stimuli, potentially allowing the species to successfully nest in human-dominated environments.

[citation needed] They are also very active birds, and can be found grasping to small twigs, and often hang upside down.