Matthew Schaefer won the 2026 Calder Trophy and got a head start on the 2027 King Clancy Trophy.

Schaefer became the second-ever unanimous winner of the NHL’s rookie of the year honor Wednesday when his family surprised him with the trophy on “GMA3” — the afternoon hour of ABC’s “Good Morning America.” The first was Teemu Selanne in 1993.

The 18-year-old defenseman and his father, Todd, both had tears in their eyes on live television as the award was presented.

While it comes as no surprise that Schaefer won the award after a dazzling season, the timing very much did.

Schaefer didn’t have any knowledge of it, but his dad and brother were put up in the same New York City hotel he was on Tuesday night. Todd had to pretend his FaceTime wasn’t working to avoid the surprise being spoiled.

“I thought they were still at home,” Schaefer said later, at an event at Northwell Cohen Children’s Medical Center, where he visited children affected by cancer and marked the future opening of the Jennifer Schaefer Child Support Center, named in honor of his late mother. “To be able to experience that with them, obviously my mom — when I got drafted and won this trophy, I think my mom’s a big part of it that comes to mind right away. Just with how much she’s done for me and my family and how she brought me and my brother up. Just the person she was. I’m so lucky to be able to do this to really help, cause I’ve been through it with my mom.”

Jennifer Schaefer died of breast cancer when Matthew was 16. Her story — and helping kids who have a parent with cancer or who have experienced the same loss he did — is a huge part of his own character.

The room, intended as a place for kids to wait while their parents undergo treatment, will open this October thanks to a $150,000 gift from the Islanders Children’s Foundation, Northwell and the Islanders. Schaefer plans to visit throughout the season.

For now, he’ll go back to his hometown of Stoney Creek, Ontario on Thursday for the summer, but Long Island — a place he knew nothing about a year ago — has become the place where Schaefer intends to leave a lasting mark.

“It’s funny, cause Long Island feels like home to me now and I never want to leave,” Schaefer told The Post.

If the Islanders have their way, he never will.

“He knows there’s one mission on the ice: to win the Stanley Cup. But in the meantime while we’re moving towards winning the Cup, he wants to be active in the community, he wants to be present, he wants to be there,” co-owner Jon Ledecky said. “After every game he’s meeting children who have some affliction or family with cancer. He walks the walk, he talks the talk. It’s just amazing to watch this young man blossom and continue to mature.”

Schaefer is the sixth member of the franchise to win the Calder, the last being Mathew Barzal in 2018. You could fill a page with the records he set this season.

Among them: most points by an 18-year-old defenseman, most goals by a rookie defenseman, youngest player ever to win the Calder.

If general managers around the league had to pick a player to start a franchise with, there’s a good chance Schaefer would go No. 1 overall.

“I honestly knew not much about Long Island or New York [last year],” Schaefer said. “Now I feel like I know everything. The food is off the charts, everything about Long Island. There’s so much to do. You got the Hamptons, you got a lot of beaches around, you got a lot of golf courses. You can go in the city if you need. Just everything about it, but especially the people. The people make it the best.”