Stejneger's scoter was described by the American ornithologist Robert Ridgway in 1887 and given the binomial name Oidemia stejnegeri.

The males of both species are very similar and best distinguished by head shape; White-winged scoters tend to have "two-stepped" profile between the bill and the head, compared to the long "Roman nose" profile of Stejneger's scoter similar to that of a common eider.

Though previously considered rare in North America, Stejneger's scoter may be a regular visitor and possible breeder in Western Alaska, with sightings in Nome, Saint Paul Island and Gambell.

A Stejneger's Scoter was seen in Helena Valley, Montana between April and May 2015, the only confirmed North American occurrence of the species south of Alaska.

[7] Stejneger’s scoter is also a rare vagrant to Europe and has been recorded from France, Finland, Poland,[8] Iceland, Ireland, Norway[5] and Scotland.