The Cinnamon-bellied Flowerpiercer is a nectar-feeding bird of the Mesoamerican highlands. Three allopatric subspecies are recognized, with genetic and plumage differences across the Isthmus of Tehuantepec.
Males have gray upperparts and cinnamon underparts. Western birds have cinnamon extending to the throat; two eastern subspecies have gray throats and deeper cinnamon below.
It feeds mainly on nectar. A western Mexican study recorded two seasonal peaks in breeding and molt; soft fruit was proposed as a possible energy source when resources were limited.
An extinction-risk assessment has not been added yet.