As the February 29 trade deadline approached, Reimer's future with the rebuilding Maple Leafs became uncertain. On February 27, 2016, two days before the deadline, Reimer was traded to the San Jose Sharks (alongside Jeremy Morin) in exchange for Alex Stalock, Ben Smith and a conditional fourth-round pick in the 2018 NHL Entry Draft (condition dependent on the Sharks reaching the Stanley Cup Finals, a condition met, converting the pick to a third-round pick on May 25, 2016). Reimer had the best five-on-five save percentage and the best Fenwick save percentage in the NHL for the 2015–16 season (1,200 minutes minimum time on ice) at .9404 and .9573 respectively.