On June 30, 2016, the Dodgers traded Pfeifer and Caleb Dirks to the Atlanta Braves for Bud Norris, Dian Toscano, a player to be named later (Alec Grosser), and cash.
In 34 combined games between Great Lakes, Rancho Cucamonga, Carolina and Mississippi, Pfeifer posted a 4–1 record and 3.02 ERA with sixty strikeouts in 47+2⁄3 total innings.
[12] Following his father's death on July 1, 2018, Pfeifer planned to retire from professional baseball and enroll in law school after the 2019 season ended.
[16] On March 20, 2021, Pfeifer signed a minor league contract with the San Francisco Giants organization that included an invitation to MLB Spring Training.
[17] He pitched to a 7.13 ERA over 35+1⁄3 innings split between the Triple-A Sacramento River Cats and Double-A Richmond Flying Squirrels, making 4 starts and 10 appearances in relief.