The Patriots will add $5 million in performance-based incentives to Brady's contract by this weekend, multiple media outlets reported on Thursday.
Brady, who won his third NFL Most Valuable Player Award in 2017, is scheduled to make $15 million this season -- $14 million in base salary and a $1 million roster bonus. He currently is set to count $22 million against the Patriots' salary cap this year because of a $7 million charge on a previous signing bonus.
The 41-year-old Brady is under contract with the Patriots through 2019 season. He has said he would like to play until he's 45 years old.
The highest-paid quarterback in the NFL is currently Atlanta Falcons star Matt Ryan, who signed a deal worth $30 million per season. Green Bay Packers quarterback Aaron Rodgers is awaiting a new contract, however.
Brady has led the Patriots to eight Super Bowl appearances in 17 seasons since taking over as the team's starter early in the 2001 campaign.
A four-time Super Bowl MVP, Brady threw for a league-best 4,577 yards along with 32 touchdowns and only eight interceptions last season.