Chara was hoping to add another Stanley Cup championship after winning one with the Boston in 2011. He also reached the Stanley Cup Final with the Bruins in 2013 and 2019.
Chara said he enjoyed his experience with Washington this season. The Capitals (36-15-5) were second in the eight-team MassMutual East Division, losing a tiebreaker with the Pittsburgh Penguins for first place.
"Since Day One, everybody welcomed me with open arms and all the credit goes to the coaching staff, trainers, all my teammates," he said. "They did an amazing job welcoming me and making that transition as easy as possible and I really enjoyed it. It was a great time spent here and a lot of fun. We played some great hockey."
The most difficult part was living apart from his wife, Tatiana, their 12-year-old daughter Elliz and 5-year-old twin sons Zack and Ben, who remained in Boston.
"Definitely that was one of those things that I found the most challenging, being away from my family," Chara said. "But at the same time, the accommodation and the environment I was in made it much easier and better than I expected. So, looking forward to seeing my family, my kids again every day, but definitely that will be a factor going into the decision I'll be making in the future."
Selected by the New York Islanders in the third round (No. 56) of the 1996 NHL Draft, Chara has scored 666 points (207 goals, 459 assists) in 1,608 regular-season games for the Capitals, Bruins, Islanders and Ottawa Senators, and 70 points (18 goals, 52 assists) in 200 NHL playoff games.
The winner of the Norris Trophy voted as best defenseman in the NHL in 2008-09, Chara is fifth among defensemen in NHL history in regular-season games, trailing Ray Bourque (1,612), Larry Murphy (1,615), Scott Stevens (1,635) and Chris Chelios (1,651) and would be within reach of breaking Chelios' NHL record if he plays another season.
"I think he's uncertain on what he wants to do," Capitals general manager Brian MacLellan said Wednesday. "I thought he played great for us, he was a great addition, I thought our third pair was solid all year with him and (Nick) Jensen. I think we'll wait to talk to him to see what his plan is before we decide that."