The team announced the deal on Monday as Marchand prepares to play for Canada in the finals of the hockey World Cup.
The 28-year-old Marchand, who could have become an unrestricted free agent next summer, had a career-high 37 goals and 60 points last season. In seven NHL seasons — all with the Bruins — he has 153 goals and 136 assists.
“Boston has become my second home,” Marchand said. “I really believe in our team and our group and what we’re working towards.”
His recent play for Canada has opened eyes across the league. Playing mostly on a line with Pittsburgh Penguins forward Sidney Crosby and perennial Boston Bruins linemate Patrice Bergeron, Marchand is second to Crosby in World Cup scoring with five points and is tied for the tournament lead with three goals.
Canada will face Team Europe in the best-of-3 finals starting Tuesday.
“The exposure and to be able to play on a team with these calibre of players, it’s incredible,” Marchand said about playing for Canada in the World Cup. “When you get that confidence to know that you can play at that level, it feels really good, for one. And it pushes you to another level.”
Marchand was a member of Boston’s Stanley Cup-winning team in 2011, with 11 goals in the playoffs, the second-most on the team. Marchand started that season, his rookie year, on the fourth line. By the end he was skating among the Bruins’ top six forwards. He would have been a coveted player had he hit the open market in 2017, especially after his breakout performance on the World Cup stage.
“Right now where is with Team Canada, he’s also very respected by his teammates for the way he prepares, the way he plays and everything else,” said Bruins coach Claude Julien, who is serving as an assistant to Mike Babcock with Canada. “So he’s come a long ways.”