Kumerow signed with the Cincinnati Bengals as an undrafted free agent on May 8, 2015.[3] He was released on September 5, 2015, and was signed to the practice squad the next day, where he spent his entire rookie season.[4][5] He signed a reserve/future contract with the Bengals on January 11, 2016.[6]
Kumerow was released by the Bengals on September 3, 2016, and was signed to the practice squad during the next day.[7][8] He was promoted to the active roster on December 27, 2016.[9]
On August 9, 2017, Kumerow was waived/injured by the Bengals after suffering an ankle injury and was placed on injured reserve.[10] He was released on September 22, 2017 with an injury settlement.
On December 26, 2017, Kumerow was signed to the Green Bay Packers' practice squad.[13] He signed a reserve/future contract with the Packers on January 2, 2018.[14]
On September 3, 2018, Kumerow was placed on injured reserve.[15] He was activated off injured reserve on December 1, 2018[16] and made his NFL debut the following day, in a week 13 loss to the Arizona Cardinals. He also recorded his first career reception, an 11-yard pass from Aaron Rodgers, during that game. On December 23, he scored his first NFL touchdown on a 49-yard reception against the New York JetsatMetLife Stadium.
Kumerow returned to the Packers on March 11, 2019.[17]
On April 25, 2020, the Packers re-signed Kumerow as an exclusive-rights free agent, which kept him under contract for Green Bay for another year.[18][19] He was released during final roster cuts on September 5, 2020, shortly after Rodgers had publicly praised his play.[20] As a result, Kumerow's release was later reported as a tipping point for Rodgers, who had developed a rapport with the receiver and was upset with Packers management over his departure.[21]
On September 8, 2020, Kumerow was signed to the practice squad of the Buffalo Bills.[22] He was elevated to the active roster on November 7, November 14, and November 28 for the team's weeks 9, 10, and 12 games against the Seattle Seahawks, Arizona Cardinals, Los Angeles Chargers, and reverted to the practice squad after each game.[23][24][25] He was promoted to the active roster on December 2, 2020.[26] Kumerow caught a touchdown pass from Josh Allen against the Denver Broncos in week 15, helping convert a second and goal from the 22-yard line.[27] He was waived on December 24, 2020 with starter John Brown returning from injured reserve.[28]
On December 25, 2020, Kumerow was claimed off waivers by the New Orleans Saints.[29] He was waived on January 9, 2021.[30] On January 13, 2021, Kumerow re-signed with the Saints practice squad.[31][32] He was released on January 18.[33]
On January 26, 2021, Kumerow signed a reserve/futures contract with the Bills.[34] In the 2021 preseason, Bills quarterback Josh Allen joked that Kumerow was his favorite wide receiver, because his only regular season catch for the Bills was for a touchdown.[35]
On March 10, 2022, Kumerow signed a one-year contract extension with the Bills.[36] On June 16, Kumerow was released by the Bills for salary cap purposes and was re-signed the next day.[37] On November 17, after an ankle injury in a game against the Minnesota Vikings, he was placed on injured reserve.[38]
Kumerow never re-signed with the Bills and remained a free agent throughout the 2023 off-season.[39]
