Kuemper, 32, agreed to a $26.25 million deal that carries an average annual value of $5.25 million against the salary cap.
"You never know where you're going to end up," Kuemper said. "Everything happens for a reason and it worked out and ended up with a great organization, a great team and super excited for it.''
Just a short while later, the Capitals found his backup, signing Charlie Lindgren to a three-year deal at an average of $1.1 million.
There was heavy buzz about the Kuemper move at the NHL draft after the Capitals traded Vitek Vanecek to the New Jersey Devils. It increased when the Capitals walked away from restricted free agent goalie Ilya Samsonov, who subsequently signed with the Toronto Maple Leafs.
Nearly a year ago to the day, Kuemper joined the Avalanche, after Colorado goaltender Philipp Grubauer signed with the expansion Seattle Kraken. He was coming off a season that made him a Vezina Trophy finalist, and his free agent offers were many, leaving a gaping hole in the Avalanche net.
Colorado was also coming off winning the Presidents' Trophy as the league's best team but losing in the second round of the playoffs, so the team quickly snared Kuemper the same day that Grubauer bolted.
Colorado swung a deal with Arizona for the goalie. He had been a part-time player his entire career, sometimes due to injuries, but had shown flashes of being something more.
Colorado's gamble clearly paid off. Kuemper won 37 games with a .921 save percentage in the regular season. He won 10 more games during the playoffs and was on the ice when the Avalanche hung on for a 2-1 win over Tampa Bay in Game 6.
The question for Colorado was finding a contract number and term for a goalie who is 32 years old. Kuemper is coming off a two-year, $9 million contract, and joins a Washington team that lost in Round 1 last season to the Florida Panthers.
The 28-year-old Lindgren, who has seen limited action in six NHL seasons, started four games for the St. Louis Blues last season, with a 1.22 goals against average and .958 save percentage.
Since the Cup Final ended in late June, 19 goaltenders who played in the NHL last season are with different teams.
"It changed quite a bit,'' Capitals general manager Brian MacLellan said. "A lot of people (were) jockeying for limited amount of guys and seemed like seats filled up and then there was a pause and there was only a certain amount left and teams went from there.''
The Associated Press contributed to this report.