Breeds over the far north of Asia east of the Yenisey Basin, and North America. It winters south, on the Great Lakes, the coasts of the northern USA and the southern coasts of Canada, and Asia as far south as China.
Subspecies
Considered by some authors to be a subspecies of Velvet Scoter (Melanitta fusca). Not recognized as a species by BirdLife International.
The following 2 subspecies are recognised:
stejnegeri Ridgway, 1887 - Siberia, from Yenisey basin east to Kamchatka, south to Mongolia. Considered by some authors to be a subspecies of Velvet Scoter (Melanitta fusca). Considered by some authors to be a distinct species, Siberian Scoter (Melanitta stejnegeri).
deglandi (Bonaparte, 1850) - Alaska and Canada, east to Hudson Bay. Considered by some authors to be a subspecies of Velvet Scoter (Melanitta fusca). Considered by some authors to be a distinct species, White-winged Scoter (Melanitta deglandi).