Area code 516 serves Nassau County on Long Island, New York. Introduced in 1951 as a split from area code 914, it was once used for all of Long Island before Suffolk County was assigned area code 631. 516 covers a dense suburban region east of New York City, with a high standard of living, commuter culture, and historic ties to New York’s expansion. It is set to be overlaid with area code 363, making ten-digit dialing mandatory. Area code 516 is a well-known symbol of Long Island affluence and identity, commonly referenced in pop culture and regional pride.