"I'm really excited to have this done, excited that I get to be a Seahawk for a long, long time," Wagner said in a statement released by the team. "Like I've always said, I want to play my entire career here, and feel like today is a step toward that."
The 29-year-old becomes the highest paid inside linebacker at $18 million per year. He was blunt in May that he wanted to become the new highest-paid linebacker in the NFL, surpassing the $17 million-per-year average C.J. Mosley earned from the New York Jets.
"He deserves to be the highest-paid linebacker. Ain't nobody better than him in the game and that's just the honest truth," quarterback Russell Wilson told reporters after practice Friday.
Wagner reported to training camp this week, despite not having a new deal, but did not participate in practice.
Former teammate Earl Thomas suffered a fractured leg last season in the final year of his contract in Seattle after not getting a new deal so it's no surprise that Wagner was cautious with his body this off season.
Wagner finished last season with 138 tackles, six tackles for loss and one interception.