Zimmer signed with the Buffalo Bills as an undrafted free agent on May 6, 2016.[2] He was waived by the Bills on August 30, 2016.[3]
New Orleans Saints
On December 13, 2016, Zimmer was signed to the practice squad of the New Orleans Saints.[4] He signed a reserve/future contract with the Saints on January 2, 2017.[5] He was waived on September 2, 2017.[6]
Montreal Alouettes
Zimmer signed with the Montreal Alouettes of the Canadian Football League on September 21, 2017, and was added to the team's practice roster.[7] He was promoted to the active roster and appeared in the Alouettes' final game of the season, recording three tackles and one sack.[8]
Atlanta Falcons
On April 17, 2018, Zimmer was signed by the Atlanta Falcons.[9] Zimmer made the Falcons' 53-man roster, and made his regular season debut in Week 3.[10] He was waived by the Falcons on October 2, 2018, and was re-signed to the practice squad.[11][12] On December 4, 2018, Zimmer was signed to the Falcons’ 53-man roster.[13]
On August 31, 2019, Zimmer was waived by the Falcons and was signed to the practice squad the next day.[14][15]
Cleveland Browns
On December 3, 2019, Zimmer was signed by the Cleveland Browns off the Falcons' practice squad.[16] The Browns waived Zimmer with a non-football injury designation on July 31, 2020.[17]
Buffalo Bills (second stint)
On August 16, 2020, Zimmer signed with the Buffalo Bills.[18] He was waived on September 5, 2020, and signed to the practice squad the next day.[19][20] He was elevated to the active roster on September 12 and October 19 for the team's weeks 1 and 6 games against the New York Jets and Kansas City Chiefs, and reverted to the practice squad the day after each game.[21][22] He was signed to active roster on October 21.[23]
In Week 8 against the New England Patriots, Zimmer made a key play late in the fourth quarter, punching the ball out of Patriots quarterback Cam Newton's hands on a quarterback keeper as New England was driving down the field to either tie or win the game. The forced fumble and recovery by teammate Dean Marlowe sealed a 24–21 Bills win.[24]
In Week 10 against the Arizona Cardinals, Zimmer recorded his first career sack on Kyler Murray during the 32–30 loss.[25] During the Bills' Divisional Round matchup against the Baltimore Ravens, Zimmer recorded a top speed of 18.45 miles per hour on an interception return, which was the second fastest speed by a Defensive Tackle during the 2020-21 season.
During the 2021 season, Zimmer was placed on injured reserve with a season-ending knee injury on November 11.[26] He became a free agent after the season, but was re-signed to the Bills' practice squad on October 4, 2022.[27]
Miami Dolphins
On November 23, 2022, Zimmer was signed by the Miami Dolphins off the Bills' practice squad.[28] On December 31, Zimmer was placed on season–ending injured reserve with an undisclosed injury.[29]