11779 -- U.S. ZIP code Municipality (1990): LAKE RONKONKOMA, New York All ZIPs for this municipality (1990): 11779 Population (2000): 39321 Housing Units (2000): 13395 Land area (2000): 13.451655 sq. miles (34.839625 sq. km) Water area (2000): 0.353241 sq. miles (0.914889 sq. km) Total area (2000): 13.804896 sq. miles (35.754514 sq. km) Located within: New York (NY) Location: 40.818826 N, 73.118703 W