Tomlin is also signed through 2020.
A symbol of the franchise's consistency in the 21st Century, Colbert has been with the Steelers since 2000. He spent the first 11 years in the front office as director of football operations before taking over the helm of general manager in 2010.
"I have been very fortunate to have been a part of this organization over the last 17 years," said Colbert, a Pittsburgh native. "I am very thankful for the opportunity to continue to be a part of our annual pursuit of a championship."