[3] Three subspecies are recognized, the nominate A. n. nigrirostris (Waterhouse, 1839), A. n. occidentalis (Chapman, 1915), and A. n. spilorhynchus (Gould, 1858).

Their face and throat are white becoming pale blue on the breast; their thighs are chestnut and their undertail coverts are red.

[5] The subspecies of black-billed mountain toucan are found thus:[2][5] The black-billed mountain toucan inhabits a variety of landscapes including cloudforest, subtropical to temperate montane forest, and more open areas such as croplands near forest and open sites with scattered trees.

[5] The black-billed mountain toucan mostly forages in the forest's canopy, in pairs or in small family groups.

[5] The IUCN originally assessed the black-billed mountain toucan as Near Threatened but since 2004 has rated it as being of Least Concern.

Deforestation has left its habitat fragmented in most of its range, leading to the species' being found locally rather than continuously.