Mountains of central Costa Rica (Aguacate Mts) south through Panama (Bocas del Toro, Chiriquí, Veraguas, Coclé and eastern Darién) to adjacent western Colombia (Cerro Tacarcuna).
 
Population
Estimated population is unknown (2010).
Sooty-faced Finch (Arremon crassirostris) [XC518496]
by Pedro Luis Castillo from San Gerardo Biological Station, Guanacaste, Costa Rica (call)
Sooty-faced Finch (Arremon crassirostris) [XC271075]
by Hans Matheve from Finca Lerida, Panama (song)
Subspecies
Often placed in genus Lysurus. On basis of similarities in molecular data, plumage, voice, behaviour and micro-habitat, this genus, and also, Buarremon, now subsumed in present genus. Probably forms a superspecies, and sometimes considered conspecific, with Olive Finch (Arremon castaneiceps).
Proposed subspecies eurous (described from Cerro Tacarcuna, in eastern Panama), supposedly duller and with darker crown, known from only a single specimen and considered untenable.