The 22-year-old forward, who was a restricted free agent, had an NHL career-high 50 points (25 goals, 25 assists) in 82 games with Buffalo last season. He was third on the Sabres in points and was tied with Jack Eichel for first in goals.
"This is where I want to be," Reinhart told the Sabres website Thursday. "Happy to be back. Really looking to starting on the right note when the [regular season begins Oct. 4].
"It was probably one of the most challenging weeks, weeks and a half I've been a part of. I think looking back on it, the best thing I did was come in early and be around the guys because now it just feels like I missed a few days and I'm right back with the team after you usually would with an injury."
The Sabres selected Reinhart, son of former NHL defenseman Paul Reinhart, at No. 2 in the 2014 NHL Draft. He has 140 points (65 goals, 75 assists) in 249 NHL games with Buffalo.
"At the end of day, we all wanted Sam to be here," general manager Jason Botterill said. "From Day One, it's been evident that Sam wants to be part of our solution in Buffalo."
The Sabres (25-45-12) finished last in the Eastern Conference last season.
"I think the best thing for the team and myself was to be here as soon as possible, and I am just thrilled we were able to agree on terms and get back and not affect opening day for me or the team," Reinhart said. "I think today was a great practice for me to come back in. It wasn't crazy by any means but the pace was up. I felt comfortable. Obviously it's going to take a day or two but I'm happy with how it went."
Sabres coach Phil Housley said Reinhart fit right in at practice. Buffalo opens the season Oct. 4 against the Boston Bruins.
"I'm just really happy that he's back and back a part of our team," Housley said. "I thought he looked great, right up to speed."
