Mistletoe Tyrannulet from northern Honduras (and perhaps adjacent Belize; Jones et al. 2000) and eastern Nicaragua through Costa Rica and Panama, and into the lowlands of extreme northwest corner of Colombia along the Panama border. It primarily occurs in the lowlands, e.g., up to 1400 m in Honduras (Gallardo 2014) and to 1200 m in Nicaragua (Chavarría-Duriaux et al. 2018), but in Costa Rica it is found, uncommonly, up to 3000 m (Stiles and Skutch 1989).
Mistletoe Tyrannulet is thought to be a resident throughout its range.