The deal with the three-time All-Star outfielder is the team's most expensive since Sandy Alderson took over as general manager. Granderson agreed to sign with the Mets on Friday, and the contract was finalized Monday during the winter meetings.
Granderson, who turns 33 in March, hit .229 with seven homers and 15 RBIs this year for the Yankees, when wrist and hand injuries limited him to 61 games. He surpassed 40 homers in each of his previous two seasons in pinstripes.
New York also signed free-agent outfielder Chris Young to a $7.25 million, one-year contract this off-season.