He has been a defensive coach since he started as a
student assistant at
Virginia Tech in 1983. including two with the
Maryland Terrapins (1997, 2006–2008) and re-joining Holtz with the
South Carolina Gamecocks (1999–2003). On December 6, 2008, it was announced that Cosh would return to Kansas State for a second time under coach Snyder (when Snyder decided to come out of retirement to help the Wildcats) as assistant head coach (to Snyder) and co-defensive coordinator alongside
Vic Koenning. Cosh will have now served as a defensive coordinator in five of the six
BCS conferences (Big Ten, SEC, ACC, Big 12, and Big East). On February 4, 2016, Cosh was named defensive coordinator at the
University of Richmond. He followed
head coach Danny Rocco to the
University of Delaware as the defensive coordinator and defensive backs coach on January 5, 2017. On July 21, 2021, Cosh was named defensive coordinator at
Christopher Newport University. 2022 Hampton University defensive coordinator. ==Personal life==