The 24-year-old forward, who was a restricted free agent, was scheduled to have a salary arbitration hearing Monday.
"It's a crazy process. I guess it's a little bit awkward and I was just really happy to get the deal done before that meeting began," Aston-Reese said. "You hear stories and things like that. It's no coincidence that only, what, five percent actually go through with the meeting. I was really relieved to avoid that."
Aston-Reese had 17 points (eight goals, nine assists) in 43 games with the Penguins last season. He had no points in four Stanley Cup Playoff games.
"Zach is a responsible player who plays a solid two-way game," Penguins general manager Jim Rutherford said. "He has a heavy style of play that is especially effective on the forecheck and penalty kill."
Signed as an undrafted free agent by Pittsburgh on March 14. 2017, Aston-Reese has 23 points (12 goals, 11 assists) in 59 regular-season games and one assist in 13 playoff games for the Penguins.
"I think throughout the last two seasons, I've seen minutes on the first line and I've seen minutes on the fourth line. Wherever I've been, I feel I've been able to do my job and do what's asked of me," Aston-Reese said.
NHL.com correspondent Wes Crosby contributed to this report
