The 23-year-old defenseman, who was a restricted free agent, avoided a salary arbitration hearing scheduled for July 24.
Pionk had an NHL career-high 26 points (six goals, 20 assists) in 73 games with the New York Rangers last season. He was acquired by Winnipeg along with the No. 20 pick in the 2019 NHL Draft (Ville Heinola) in a trade with New York on June 17 for defenseman Jacob Trouba.
Signed by New York as a free agent on May 1, 2017, Pionk has 40 points (seven goals, 33 assists) in 101 regular-season games. He has never played in the Stanley Cup Playoffs.