McCutchen, a five-time All-Star and the 2013 National League MVP, signed a $51.5 million, six-year deal in 2012 that included the option, which had a $1 million buyout attached.
McCutchen, 31, hit a team-high 28 homers and drove in 88 runs for the Pirates this season. He began the season in right field but returned to center after Starling Marte was suspended for 80 games for a positive drug test.
Pittsburgh explored trading McCutchen last offseason. General manager Neal Huntington said repeatedly near the end of 2017 that Pittsburgh's best chance at winning in 2018 is with McCutchen in the lineup.