The deal is set to pay Rask $4 million per season through the 2021-22 campaign.
The young star ranked second on the team this past season with 48 points, the most of his career in a single year. He finished with 21 goals and 27 assists in 80 games for that point total. 18 of those points came on the power play, as he had five goals and 13 assists with the man-advantage.
The former 42nd overall pick in 2011 made his NHL debut in the 2014-15 season. He had 11 goals and 22 assists in his rookie year, and a rise in those numbers called for this deal. General manager Ron Francis described the logic of this contract by saying that Rask has "gotten better every season" and called the the center a "big part of this team's present and future."