General manager Doug Wilson announced on Monday the deal to keep the AHL's top goaltender under contract. Grosenick had been eligible to be an unrestricted free agent in July.
Grosenick, 27, ranked second in the AHL with 30 wins, tied for second with a .926 save percentage and was third in goals-against average at 2.04 this past season. He also had a league-leading 10 shutouts.
In 2014-15, Grosenick became the first Sharks goalie to record a shutout in his NHL debut by making 45 saves against Carolina. He went 1-1 with a .948 save percentage and 1.53 goals-against average for San Jose that season.