Area code 934 is found in the US state of New York. Area codes 631 and 934 are the telephone area codes for Suffolk County, New York, the central and eastern part of Long Island. Area code 631 was created in 1999 as a split from area code 516, and 934 was added as an overlay in 2016. Area code 934 was first put in service July 16, 2016. Currently, the largest city it serves is Brentwood, NY, and it overlaps coverage areas with area code 631. Phone numbers in the 934 area code can be found in 12 cities or locations.