The Nationals made Hoffmann the first pick in the winter meeting draft, then traded him to the Yankees. The draft is held for players with at least four years of pro ball who have been left off 40-man rosters.
Hoffmann made his major league debut last season, going 4-for-22 with one home run and seven RBIs for the Los Angeles Dodgers. He hit a combined .291 with 10 homers and 64 RBIs in Triple-A and Double-A.
Yankees general manager Brian Cashman said Hoffmann will compete for the final roster spot for the World Series champions. The 25-year-old Hoffmann also was picked in the 2003 NHL draft by the Carolina Hurricanes.
"He's got a hockey mentality, a Minnesota kid," Cashman said. "A very athletic, hard-nosed outfielder."
"We'll see where it takes us. We feel he's got great makeup. He's got ability. We project him in the future as an everyday-type player," he said.
Hoffmann and Brett Gardner could be in the mix for the last spot as a reserve outfielder.
"Gardy's a pure center fielder with blazing speed. This guy, he's got some thump. He's a big boy," Cashman said.
Teams pay $50,000 apiece for players in the Rule 5 draft. They must either remain on the major league 25-man roster or disabled list all season or be offered back to their original club for $25,000.
Baltimore picked left-hander Ben Snyder from the San Francisco organization with the third choice. The Orioles traded Snyder to Texas, completing Wednesday's trade that sent Kevin Millwood to Baltimore and Chris Ray to the Rangers.