Geiger first took up refereeing in 1988. He became a United States Soccer Federation National Referee in 2003 and officiated in Major League Soccer from 2004 to 2018. He has officiated in CONCACAF tournaments since becoming a FIFA referee in 2008, and has officiated Gold Cup and other international tournaments and fixtures. Geiger was selected for the CONCACAF U-20 Championship in 2011, where he refereed the final.