Posey was scheduled to make $8 million this season so the total deal is worth $167 million over eight years.
He also receives a $21.4 million club option for 2022 and the contract also contains a no-trade clause. Posey was under contract through the 2016 season, but this new deal buys out several years of free agency.
Posey, the 2012 National League Most Valuable Player, hit .336 with 24 home runs and 103 RBI last season, leading the team to their second world championship in three seasons.
Posey missed the majority of the 2011 season have suffering a leg injury. In four MLB seasons, Posey is batting .314 with 46 home runs and 191 RBI winning the National League Rookie of the Year award in 2010.