"Yeah, I'm happy with it. I'm ecstatic," Mankins said, per a team release. "This doesn't feel real yet, so I don't know how to take it yet, but I'm very happy to be here. Looking forward, I'm hoping to have a good season and hopefully I can help this team win games for the next six years if I make it that long."
Mankins, who has made three Pro Bowls, was set to play under a one-year, franchise-tag tender contract worth $10 million.
"It still hasn't sunk in yet," he said. "That's what guys always hope [for] -- to get to this point, and I think when you get there it takes a little while to set in, so I'm still at a little bit of a loss for words about it."
A first-round draft pick of the Patriots in 2005, Mankins sat out the first eight weeks of the 2010 season after holding out over his status as a restricted free agent. Mankins signed his tender and reported to the team on Nov. 2 and started the final nine games of the season.