Molecular data confirms that the Ash-breasted Sierra-Finch is the closest relative to the broadly sympatric Plumbeous Sierra-Finch (P. unicolor). However this pair of Sierra-Finches is not closely related to the rest of the genus, and is allied to Haplospiza and Catamenia, two genera of largely grayish finch-like tanagers. The Ash-breasted is a species of the high Andes, found typically above 2500m; its range does not extend as far north or south as that of the Plumbeous Sierra-Finch however. The Ash-breasted is a species of dry Puna, often very arid desert habitats in the highlands. It is found in various degraded habitats and does not need bogs or streams to the extent of many other highland finches. This species is sexually monomorphic in much of its range, being grayish below and darker above with indistinct streaking. A lowland desert form in Peru shows browner and more streaked females! The taxonomic position of this population needs further study. This sierra-finch is often found in flocks.