The contract begins next season and runs through 2024-25. The 27-year-old defenseman's salary cap charge this season is $2.225 million after he signed an arbitrator-awarded two-year, $4.45 million contract Aug. 5, 2017.
"Nate's turned out to be a pretty good defenseman for us," general manager George McPhee said. "There's still a lot of room for growth for Nate. He's the kind of defenseman every team in this league is looking for. ... He's become a shutdown defenseman for us."
Schmidt was suspended without pay for the first 20 games of the season Sept. 2 for violating the terms of the NHL/NHL Players' Association Performance Enhancing Substances Program. He is eligible to return Nov. 18 at the Edmonton Oilers.
"It was utterly shocking to be informed that I tested positive for a microscopic amount of a tainted substance," he said in a statement at the time. "... While I support having a strong Performance Enhancing Substances Program in place for our sport, it is difficult to accept this suspension. I understand that I will miss these games, but I do not agree with the suspension and I will not accept being labelled a cheater."
Schmidt was selected by the Golden Knights from the Washington Capitals in the 2017 NHL Expansion Draft. He helped Vegas reach the Stanley Cup Final in its first season, losing to Washington in five games.
"The knock on him was that he wasn't a good defender," McPhee said. "When paired with [Brayden] McNabb, they do a good job eating up a lot of minutes and playing against the other team's top guys."
Schmidt had 36 points (five goals, 31 assists) and a plus-19 rating in 76 games last season, and then had seven points (three goals, four assists) and a plus-7 rating in 20 Stanley Cup Playoff games. He has 79 points (13 goals, 66 assists) in 276 games for the Capitals and Golden Knights.
NHL.com correspondent Danny Webster contributed to this report.
