Bangladesh, Bhutan, China (mainland), India, Laos, Myanmar, Thailand, Vietnam.
Northern and eastern India (Sikkim and northern West Bengal eastern throughout north-eastern states; northern Eastern Ghats in eastern Orissa and north-eastern Andhra Pradesh), Bhutan, eastern Bangladesh, and north-western Myanmar.
 
Population
Estimated population is unknown (2010).
Buff-chested Babbler (Cyanoderma ambiguum) [XC659305]
by Jelle Scharringa from Sangsabi, Imphal East, Manipur, India (song)
Buff-chested Babbler (Cyanoderma ambiguum) [XC579462]
by Bram Piot from Phou Phanang, Vientiane Prefecture, Laos (song)
Subspecies
Subspecies ambigua, adjuncta, planicola and insuspecta of Rufous-fronted Babbler (Cyanoderma rufifrons) sometimes treated as included in this species.
Considered by some authors to be a subspecies of Rufous-fronted Babbler (Cyanoderma rufifrons).
The following 4 subspecies are recognised:
ambigua Harington, 1915 - Himalayas (Sikkim to Bhutan and Assam southern of the Brahmaputra). Considered by some authors to be a subspecies of Rufous-fronted Babbler (Cyanoderma rufifrons).
planicola (Mayr, 1941) - Southern part of northern Myanmar; probably also western Yunnan, in southern China. Considered by some authors to be a subspecies of Rufous-fronted Babbler (Cyanoderma rufifrons).
adjuncta (Deignan, 1939) - Northern Thailand, northern and central Laos and northern Vietnam (western Tonkin, northern Annam). Considered by some authors to be a subspecies of Rufous-fronted Babbler (Cyanoderma rufifrons).
insuspecta (Deignan, 1939) - Southern Laos. Considered by some authors to be a subspecies of Rufous-fronted Babbler (Cyanoderma rufifrons).