The contract is worth $20 million, paying Lowrie $10 million in both 2019 and 2020, a source told SNY's Andy Martino.
Completion of the deal is pending a physical, MLB.com's Mark Feinsand reports, citing a source.
The deal reunites Lowrie with his former agent, Brodie Van Wagenen, who took over as the Mets' general manager in November. Lowrie is now represented by Casey Close.
Lowrie brings depth as a versatile and productive infielder who can play second base, shortstop, and third base. He primarily played second during his last three seasons with the Oakland Athletics but did start 14 games at the hot corner last year. He also provides experience, having played on six playoff teams during 11 major-league seasons.
The Mets plan to give Lowrie everyday play in a utility role across the infield, and he could see time at first base - a position he hasn't played since 2011 - if they decide prospect Peter Alonso isn't ready yet, Mike Puma of the New York Post reports.
Lowrie just completed the best season of his career, slashing .267/.353/.448 (120 OPS+) with a career-best 23 homers and 99 RBIs across 157 games to help the Athletics reach the playoffs. He was also named an All-Star for the first time.