The Ottawa Senators selected Kramer 156th overall in the 6th round of the 2011 National Hockey League Entry Draft. After finishing junior hockey, Kramer signed a three-year entry level contract with the Senators and joined their AHL affiliate, the Binghamton Senators, where he scored 22 points and earned 545 penalty minutes in 136 games between 2012 and 2015. The Senators did not tender Kramer a qualifying offer following the 2014–15 season, making him an unrestricted free agent. Kramer joined the Manitoba Moose in July 2015 on a professional tryout contract and later signed a one-year contract with the club. The Moose re-signed Kramer to one-year contracts during the summers of 2016 and 2017.