Montz made his major league debut on September 4, 2008, for the Washington Nationals against the Atlanta Braves; in that game, he went 0-for-3.

[2] He was released on September 3, 2013, re-signed in October 2013, and played briefly during the 2014 season for Oakland's Arizona League rookie team.

Montz spent 2018 as a coach with the Portland Sea Dogs, the Boston Red Sox' Double-A affiliate in the Eastern League.

[3] In January 2019, he was named manager of the Lowell Spinners, Boston's Class A Short Season affiliate in the New York–Penn League.

[4] In January 2021, following MLB's realignment of the minor leagues, he was named manager of Boston's Class A affiliate, the Salem Red Sox.