Central and eastern Bolivia (from Cochabamba and Tarija), Paraguay and central and southern Brazil (Mato Grosso and Goiás to Rio Grande do Sul) south to Uruguay and northern Argentina (south to Catamarca, Córdoba and northern Buenos Aires). Single records from south-eastern Colombia (Leticia) and north-eastern Ecuador (eastern Napo).
 
Population
Estimated population is unknown (2010).
Blue-tufted Starthroat (Heliomaster furcifer) [XC539987]
by id from Col\u00f3n, Departamento Col\u00f3n, Entre R\u00edos, Argentina (song)
Blue-tufted Starthroat (Heliomaster furcifer) [XC580458]
by JAYRSON ARAUJO DE OLIVEIRA from Santa Rita do Novo Destino, Goi\u00e1s, Ch\u00e1cara Jayrson, Brazil (call)
Subspecies
Formerly isolated as the only species in present genus, on basis of forked tail, pointed rectrices and details of bill morphology, the remaining three species being placed in genera Anthoscenus and Lepidolarynx. However, the distinguishing features vary in a continuum between present species and Plain-capped Starthroat (Heliomaster constantii) and Long-billed Starthroat (Heliomaster longirostris), with Stripe-breasted Starthroat (Heliomaster squamosus) occupying an intermediate position, and treatment of all four as congeners now generally accepted. Some authors also merge Rhodopis.