Gartner had a solid season in 1979–80, winning the Capitals' Rookie of the Year and MVP awards, as well as being voted by their fans as the team's Most Promising Player. He also led the team with 36 goals. Gartner was traded to the Minnesota North Stars on March 7, 1989, with Larry Murphy for Dino Ciccarelli and Bob Rouse. He left the Capitals as the team's all-time leader in career goals, assists and points, as of January 2017 he stands third in goals and points and fourth in assists.