score:1
Yes, according to the Korean Tourism Organisation
Transportation card purchase locations: Transportation Center on B1F of Incheon Intβl Airport Terminal 1 & Terminal 2 (Single-journey transit card), convenience stores inside Incheon International Airport (Tmoney card), Tourist Information Center near Gates 5 & 10 on 1F of Incheon International Airport Terminal 1 (MPASS)
That's advice for arriving passengers. They also list it here:
Transportation card information: Tmoney / Exclusive Tourist Cards
Upvote:1
In 2017, I was visiting South Korea, flew into Incheon airport, got a T-Money card there and used it all the way from there on the all-stops train into the city centre where my hotel was without issue.
This should not have changed.