Hischier, 20, was the first overall pick in the 2017 NHL draft. He has two assists in six games this season, having missed Thursday's victory over the Rangers with an injury. The Swiss-born center has 37 goals and 64 assists in 157 career NHL games.
"I like the direction the organization is going in, and the confidence they give me is all a player can ask for,'' Hischier said. "We have a young, exciting team, and I am driven to try my best to help the team succeed every day. I was really welcomed here from day one, and I have always felt that I wanted to be part of the Devils.''
General manager Ray Shero said he is glad to have Hischier's deal done.
"Nico is a special person who possess a team-first mentality combined with an inner drive to succeed," Shero said. "The entire organization is thankful to him and his family for believing in our future. We are excited that he will continue to play a prominent role with us for many years to come."
The contract carries an average annual value of $7.25 million. The first season (2020-21) has a base salary of $7 million; Hischier will make $8.5 million in the final season (2026-27).
Hischier joins several young NHL players who have signed contract extensions ahead of restricted free agency in June 2020. That includes Chicago forward Alex DeBrincat (three years, $6.4 million AAV), Arizona's Clayton Keller (eight years, $7.15M AAV), Ottawa defenseman Thomas Chabot (eight years, $8M AAV) and Colorado defenseman Samuel Girard (seven years, $5M AAV).
This trend comes after last summer's restricted free-agent tension, as several star players waited until weeks before the season to sign. One of those players -- Carolina's Sebastian Aho -- inked an offer sheet with Montreal that was later matched by the Hurricanes.
With Hischier signed, the Devils have secured a part of their foundation, but the question remains whether winger Taylor Hall -- Hischier's linemate -- will remain a part of that foundation. Hall is due to be an unrestricted free agent next summer, and would be coveted if he hits the market.
Information from The Associated Press was used in this report.