Keim was set to enter the final guaranteed year of the contract he signed in 2015, though the Cardinals held an option for next season.
"Steve’s performance and accomplishments as Cardinals GM speak for themselves," Cardinals president Michael Bidwill said in the announcement. "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 team's 49-30-1 record during Keim's five seasons as GM ranks fifth in regular-season wins by a GM since 2013. The .619 win percentage ranks seventh in the NFL in that time.
Keim started as a college scout with the Cardinals in 1999, and held various other roles before becoming GM in advance of the 2013 season.
His contract lines up with that of new head coach Steve Wilks, whose four-year deal runs through 2021, but the Cardinals hold an option for 2022.