From 1990–1991, McMahon was the tight end, offensive tackle and special teams coach for the University of Nevada at Las Vegas. McMahon then spent 13 seasons (1992–2004) as an assistant coach at the University of Illinois as a wide receiver and tight end/special teams coach.[2] He then spent one year as tight end/special teams coach at East Carolina in 2005.
On September 13, 2022, McMahon was announced as Special teams coordinator of the Houston Roughnecks of the XFL[8]
Tulane
Following the Roughnecks season, McMahon returned to college football, joining Willie Fritz's Tulane Green Wave football staff as the special teams coordinator in May of 2023.[9]