Montoya spent the 2000–01 season with the U.S. National Team Development Program. Montoya began attending the University of Michigan and playing for the Wolverines ice hockey team in 2002–03. He enjoyed success at Michigan, especially during his final season in 2004–05, where he posted a record of 30–7–3. Montoya twice represented the United States at the World Junior Ice Hockey Championships, backstopping the team to its first gold medal at the 2004 tournament in Finland; he was named to the tournament All-Star team. The 2005 tournament, hosted by the United States, was a disappointing one for Montoya and the U.S., as they failed to earn a medal, losing to the Czech Republic in the bronze medal game.