Dan Graziano of ESPN reported the news.
Keim has been with the Cardinals organization since 1999 and was promoted to general manager in 2013. Arizona has made the playoffs twice under Keim, including an appearance in the 2016 NFC Championship Game.
"Steve's performance and accomplishments as Cardinals GM speak for themselves," Cardinals president Michael Bidwill said in a statement. "His role in the team’s success over the last five seasons is undeniable. This new contract ensures that he will continue to shape our success going forward and we are thrilled about that."
The Cardinals are in the midst of a major organizational change this offseason, with coach Bruce Arians and quarterback Carson Palmer retiring. Franchise wide receiver Larry Fitzgerald is also contemplating his future in football.
Keim had one year remaining on his contract, so this is likely a showing of good faith that the organization believes in him to lead them into their next chapter.