In 1983, Ryan entered the coaching ranks, while still playing, when he served as an assistant coach with Colorado College men's soccer team. Ryan retired from playing after the first MISL season of the Sting in 1985 and moved to the University of Wisconsin–Madison where he coached in various capacities until 1993. In 1991, he was named the women's college coach of the year. In 1996, he moved to Southern Methodist University where he compiled a 37-21-5 record as the women's soccer coach. In 1999, he moved back to Colorado College.
The national team finished first in first-round group play in the 2007 Women's World Cup held in China. In the quarterfinals, the team defeated England 3-0. Heading into the semifinal match against Brazil, Ryan decided to bench regular goalkeeper Hope Solo in favor of veteran goalkeeper Briana Scurry. The team subsequently lost to Brazil 0-4 (the worst defeat in the team's history) and Ryan received considerable criticism for the sudden lineup change as well as defensive-minded substitutions made when the team arguably needed more offensive players to compete against the Brazilians. On Monday October 22, 2007 U.S. Soccer President Sunil Gulati announced that Ryan's contract would not be extended past its December 31, 2007 expiration date.
Ryan accepted the position of head coach for the University of Michigan women’s soccer team on Feb. 1, 2008. He became the second head coach in the program’s 14-year history. After the team posted losing seasons in his first two years at the helm, the Michigan women's team qualified for the NCAA tournament in 2010 but lost in the first round. Through three seasons, Ryan's record at Michigan is 20-24-14.