Rand Getlin of NFL Network was the first to report word of the agreement. Getlin added that Kuechly's new $12.4 million annual salary will make him the highest-paid inside linebacker in NFL history.
Kuechly, who led the NFL in tackles in 2012 and 2014, was previously signed through 2016 after the Panthers picked up his $11 million option for that season.
Kuechly has not missed a game in his NFL career and has teamed up with outside linebacker Thomas Davis to create one of the most fearsome linebacking duos in the league.
Since 2012, the two have combined for 799 tackles, the most of any two linebackers in the league, according to ESPN.com's David Newton, citing ESPN Stats & Info. Breaking up that defensive core after next season could have prevented the Panthers from becoming one of the NFC's elite teams.
