From the 2011–12 season, while still playing, Kehrmann became a part of the Lemgo youth team setup. From the 2013–14 season he coached the „Lemgo Youngsters“ in the 3. Liga. On December 12th, 2014 he became the head coach at
TBV Lemgo, replacing
Niels Pfannenschmidt. When he took over the team was in second-to-last place, but he managed to avoid relegation in his first season. In the 2019–20 season, he won the
DHB-Pokal with the team. ==Personal life==