IIHF website lists the following:
The four teams in the Relegation Round play a single round robin series. The three teams which finish first, second and third at the end of this round play again at the 2013 IIHF Ice Hockey U20 World Championship, while the fourth-place team is relegated to the Division I Group A. Teams carry over the points they earned from the Preliminary Round from the game against the other team from the group participating in the Relegation Round.
USA and Switzerland have 3 points each so a win over Latvia on Tuesday will guarantee the Americans a spot in the 2013 World Juniors in Russia.