Area codes 860 and 959

Area codes 860 and 959 are telephone area codes in the North American Numbering Plan in the U.S. state of Connecticut. They are arranged in an overlay plan that covers most of the state, except its southwest, which uses area codes 203 and 475.

Area code 860 was created on August 28, 1995, as a numbering plan area split from area code 203, in which the latter was reduced to Fairfield County (except for Sherman) and New Haven County, plus part of Litchfield County (Bethlehem, Woodbury, and a small part of Roxbury). Dialing of area code 860 became mandatory on October 4, 1996.

Area code 959 was originally announced in August 1999 to overlay area code 860, but implementation efforts were delayed for over a decade, culminating in an effective starting date for operation of August 30, 2014. Nevertheless, all calls within Connecticut required ten-digit dialing as of November 14, 2009.