Montgomery had a strong postseason performance in 2016, playing an instrumental role in the team's championship run. Cumulatively he went 1-1, including 11 appearances, innings pitched, and a 3.14 ERA. Most notably, Montgomery relieved Carl Edwards Jr. in the bottom of the 10th inning in Game 7 of the World Series. With a runner on first base and two outs in a one-run game, he finished the game with a ground out to third base. Montgomery earned his first career save, winning the World Series for the Chicago Cubs for the first time in 108 years.