North American area code 516 is a telephone area code serving Nassau County, New York on Long Island.
Upon nationwide adoption of area codes in October 1947, Nassau, Suffolk, and the lower Hudson Valley were assigned the 914 area code. In 1951, Nassau and Suffolk counties were moved into the then-new 516 area code.
The 516 code remained unchanged until November 1, 1999, when Suffolk moved to the new 631 area code.
Coordinates: 40°44′N 73°38′W / 40.74°N 73.63°W / 40.74; -73.63