Kuechly, 24, was entering the final year of his rookie contract, and his 2015 salary will now be the average of the NFL's 10 highest-paid middle linebackers.
Kuechly has started 16 games in each of his three NFL seasons, recording at least 150 tackles in each and earning NFL Defensive Player of the Year honors in 2013 and NFL Defensive Rookie of the Year honors in 2012.
Last season, Kuechly recorded 153 tackles, three sacks, 12 pass deflections, one interception and one forced fumble. According to the Panthers' release, Kuechly's 473 tackles over the past three seasons are 44 more than any other NFL player in that time frame.
Before last season, the Panthers also exercised the fifth-year option on quarterback Cam Newton, keeping him signed through the end of the 2015 season.
- Mike Fiammetta