Bolivia from vicinity of La Paz (city of La Paz) south-western along eastern ridge of Andes to departments of Santa Cruz and Chuquisaca, and northern Argentina (northern Jujuy).
 
Population
Estimated population is unknown (2010).
Grey-bellied Flowerpiercer (Diglossa carbonaria) [XC778911]
by id from Cochabamba: near Mirador de Carahuasi 1, Bolivia (song)
Grey-bellied Flowerpiercer (Diglossa carbonaria) [XC2062]
by Miguel Castelino from Choj\u00f1a Khota, first lower camp; near Inquisivi, La Paz, Bolivia (song)
Subspecies
No subspecies.
Genus has sometimes been placed in Coerebidae or Parulidae or even, because of an apparent close relationship to Acanthidops, in Emberizidae. Molecular phylogenies indicate that it is most closely related to Xenodacnis and to Acanthidops, Haplospiza and Catamenia (the last three genera currently placed in Emberizidae), and that all clearly belong in present family. Members of this clade may also be closely related to the Oreomanes - Conirostrum clade. Forms a monophyletic group with Merida Flowerpiercer (Diglossa gloriosa), Black Flowerpiercer (Diglossa humeralis) and Black-throated Flower-piercer (Diglossa brunneiventris), and all were previously regarded as conspecific. Known to hybridize, to limited extent, with Black-throated Flower-piercer (Diglossa brunneiventris) in small area of range overlap in Bolivia (La Paz).