Bolivia (locally in northern Beni, northern Santa Cruz) and south-central and north-eastern Brazil (central Mato Grosso east to Tocantins and Goiás, extending north-eastern locally to southern Ceará and southern Piauí, and south to western Paraná and western Sío Paulo).
 
Population
Estimated population is unknown (2010).
Large-billed Antwren (Herpsilochmus longirostris) [XC701860]
by JAYRSON ARAUJO DE OLIVEIRA from Magdalena (near Orobayaya), It\u00e9nez, Departamento del Beni, Bolivia (duet, during duets de male starts and the female joins, in the last part)
Large-billed Antwren (Herpsilochmus longirostris) [XC863785]
by Fernando Igor de Godoy from Fazenda S\u00e3o Miguel, Itaj\u00e1, Goi\u00e1s, Brazil (call, song, bater de asas)
Subspecies
Thought to be most closely related to Pectoral Antwren (Herpsilochmus pectoralis) on basis of plumage and distribution, although vocalizations not closely similar.