The deal also includes $19 million in guaranteed money, according to Hightower's agency, Sports Trust Advisors, which announced the news on Twitter.
Hightower will re-sign with New England despite being coveted by multiple teams, including the Pittsburgh Steelers and the New York Jets. He earned $7.751 million in 2016, as the Patriots had picked up the fifth-year option of the five-year contract he had signed as a rookie.
Hightower visited with the Steelers on Tuesday, one day after visiting with the Jets in New York. The Jets offered Hightower a contract on Monday but withdrew the offer after he left the team's facility, a source told ESPN's Adam Schefter.
The deal to keep Hightower marked the latest high-profile move this offseason for the reigning Super Bowl champion Patriots, who also signed free-agent cornerback Stephon Gilmore and acquired star receiver Brandin Cooks in a blockbuster trade with the Saints.
Hightower, 27, was named a Patriots captain for the first time in 2016. He finished the season with 65 tackles, 2.5 sacks and eight quarterback hits.
The 6-foot-3, 265-pound Hightower has made big-time plays on the game's biggest stage. His fourth-quarter strip sack of Falcons quarterback Matt Ryan in Super Bowl LI was cited by head coach Bill Belichick as a game-changing play in the team's 25-point second-half comeback.
And with 1:06 remaining in Super Bowl XLIX, Hightower tackled running back Marshawn Lynch at the 1-yard line on the play before cornerback Malcolm Butler's dramatic interception to help the Patriots beat the Seahawks.
The Patriots have closely managed Hightower's injury situation in recent seasons, as he has played a full NFL season only once in his career. Hightower played 67.9 percent of the defensive snaps in the 2016 regular season, 54.2 percent in the 2015 regular season and 76.7 percent in the 2014 regular season.
ESPN's Adam Schefter, Mike Reiss and Josina Anderson contributed to this report.