Halak is 10-6-3 with a 2.09 goals-against average and two shutouts in 20 games this season. The move is retroactive to last Monday.
The 30-year-old was 38-17-4 with a 2.43 GAA and six shutouts last season, which was his first year with the Islanders. He missed most of the preseason and New York's first four games this year with an undisclosed upper-body injury.
Thomas Greiss will start against Toronto on Sunday night in the Islanders' first game in nearly a week because of the break for Christmas. Greiss is 9-4-3 with a 2.03 GAA.
New York recalled Christopher Gibson from Bridgeport of the AHL. Gibson was 11-5-3 with a 1.99 GAA for the Sound Tigers.
The Islanders also have Jean-Francois Berube on the roster.