Zach Thornton joined D.C. United before the 2015 MLS season as Director of Goalkeeping and assistant coach from Villanova University, where he served as the Associate Head Coach for the Men's Soccer team from January 2013 -January 2015. Prior to Villanova, Thornton volunteered his time at Loyola University for the 2012 season. He also holds a U.S. Soccer Federation National "B" Coaching License.

Thornton enjoyed an illustrious playing career, earning nine caps for the U.S. National Team, playing 16 season in MLS and for the Portuguese giant Benfica from 2003-2004, where he won the Portuguese Cup. Thornton won one MLS Cup, four Lamar Hunt U.S. Open Cups, one Supporters' Shield and was MLS runners-up in 2000 and 2003. He was a six-time MLS All-Star, earned MLS Goalkeeper of the Year honors twice, was named the MLS Comeback Player of the Year and was named to MLS Best XI twice.

He was also the Chicago Fire Team MVP in 2002, Chicago's Defensive Player of the Year in 2001 and '02 and Chivas USA's Team MVP in 2009. Thornton was named as an alternate for both the 1996 Olympics and the 2002 World Cup.

Before playing professionally, Thornton was an NSCAA All-American at Loyola University for soccer in 1993 and 1994, and earned All American Honor for lacrosse in 1994 and 1995. He was inducted into the university's Hall of Fame for both sports in 2003. At Essex Community College of Baltimore County, he was inducted into the NJCAA Soccer Hall of Fame in 2000, the Lacrosse Hall of Fame in 2015, and the CCBC Hall of Fame for both sports in 2012.