Severino, 30, declined a qualifying offer from the Mets worth $21.05 million, meaning the team will receive draft pick compensation for his signing with the A’s. The compensatory pick will be after the fourth round.
The guaranteed payout is the largest in A’s franchise history.
A workhorse in the Mets’ rotation last season, Severino pitched to a 3.91 ERA over 182 innings in 31 starts.
The right-hander arrived on a one-year deal worth $13 million as he looked to resurrect a career that had been plagued by injuries with the Yankees.