Rongen was one of the inaugural coaches in MLS, coaching the
Tampa Bay Mutiny in their first season in 1996, with whom he won the MLS regular season, and also won
MLS Coach of the Year Award. After a year with the Mutiny, Rongen moved to the
New England Revolution, which he would coach in 1997 and 1998. After the Revolution, Rongen succeeded
Bruce Arena as the head coach of
D.C. United, which he would lead to an
MLS Cup in 1999. However, Rongen lost his job with United in 2001, and was replaced with
Ray Hudson. Upon leaving United, Rongen was appointed head coach of the
United States U-20 men's national soccer team, which he coached from 2001 to his appointment as head coach of
Chivas USA for the team's inaugural season in 2005. However, ten games into the season, with the team's record standing at one win, one tie, and eight losses, he was let go of his head coaching duties. Rongen was appointed head coach of the Under-20 United States men's national team again in 2006 and led the team to the
2007 FIFA U-20 World Cup and
2009 FIFA U-20 World Cup. He was fired from that position in May 2011.
Rongen became director of
TFC Academy prior to the 2012 season, joining countrymen
Aron Winter and
Bob de Klerk at
Toronto FC