The 25-year-old goalie could have become a restricted free agent after this season. Owner Francesco Aquilini had announced in a tweet March 31 that the Canucks had given Demko a five-year contract, but financial terms were not disclosed.
"Thatcher Demko has been a guy that, we drafted him, we've developed him I think properly, we've been careful every step of the way," general manager Jim Benning said Friday. "We got him up here in Vancouver, we've made sure that he was surrounded by an experienced goalie and then when he's been ready to kind of take over as the guy, he's kind of shown us that this year and he's done that, so we're excited to get him signed for the next five years. We expect his development to keep getting better and better and he's had an excellent season for us so far so we're excited about that signing."
Demko is 12-12-1 with a 2.77 goals-against average, .917 save percentage and one shutout in 25 games in his second full NHL season. He has started 19 of Vancouver's 26 games since Feb. 1, with Braden Holtby starting seven. Holtby signed a two-year, $8.6 million contract with the Canucks this offseason.
"I think there's a lot on the table and I'm just really excited to get the opportunity to take that next step," Demko told Sportsnet in November. "I want to be in Vancouver as long as I can. I want to be the guy."
Demko was 8-3-0 with a 2.15 GAA and an NHL-high .937 save percentage in March (minimum 10 games). He was named the NHL Second Star for the week ending March 7 after going 3-0-0 with a 1.00 GAA, .969 save percentage and his first regular-season NHL shutout, a 4-0 win against the Winnipeg Jets on March 1.
Selected by Vancouver in the second round (No. 36) of the 2014 NHL Draft, Demko is 30-25-4 with a 2.92 GAA and .911 save percentage in 62 NHL regular-season games (59 starts) and 2-1 in four Stanley Cup Playoff games (three starts).
He helped the Canucks rally after they trailed 3-1 in the Western Conference Second Round last season against the Vegas Golden Knights, but Vancouver lost the best-of-7 series in seven games.
"I think it showed not only me, but it showed his teammates and coaches, our fans and the media, that he is the guy we thought he could turn out to be," Benning said. "We believed that's what he was capable of, but to actually see it for three games and for everybody else to see it, I think it was fantastic."
Demko made 42 saves in a 2-1 victory in Game 5 to become the first rookie goalie to win an elimination game in his playoff debut since Jose Theodore for the Montreal Canadiens against the New Jersey Devils in Game 5 of the 1997 Eastern Conference Quarterfinals. Demko made 48 saves in a 4-0 win in Game 6, the most in a postseason shutout by an NHL rookie, and 128 saves on 130 shots in the series (0.64 GAA, .985 save percentage).
"I think the biggest thing I take away from that was just the mental step that I took," Demko said. "That's the thing that's probably the biggest adjustment going through your career, having that mentality, creating that confidence and sustaining that confidence."
The Canucks have had six straight games postponed because 25 people associated with the team have tested positive for COVID-19, a total of 21 players and four staff members. Vancouver is tied with Calgary for fifth in the seven-team Scotia North Division, eight points behind Montreal. The top four teams will make the playoffs.