Rierden, 43, joins Washington after spending the past four seasons working as an assistant with the Pittsburgh Penguins under Dan Bylsma, who was fired earlier this month. Reirden and fellow Pittsburgh assistant Tony Granato were let go when the Penguins hired Mike Johnston as Byslma's replacement earlier Wednesday.
During his time with Pittsburgh, Reirden primarily worked with the Penguins' defensemen and power play.
Before joining Bylsma's staff, Reirden served as the coach of the Penguins' American Hockey League affiliate in Wilkes-Barre/Scranton for two seasons. He also served as an assistant coach for one season at Bowling Green State University, where he starred playing for Jerry York from 1990-94.