Area codes 617 and 857

Area codes 617 and 857 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Massachusetts, serving the city of Boston and several surrounding communities such as Brookline, Cambridge, Newton and Quincy.

Area code 617 is one of the original North American area codes created in October 1947, when it served the eastern two-thirds of Massachusetts, from roughly the western end of Worcester County to Cape Cod and the South Coast.

Area code 617 was assigned to the more populous eastern portion, stretching from roughly the western end of Worcester County to Cape Cod and the South Coast.

The rest of the state, roughly everything from Hardwick westward, was served by area code 413.

In July 1988, most of the western, northern, and southern portions of the old 617 territory, including Worcester County, the Merrimack Valley, the South Coast, and the Cape and Islands, were split off as area code 508.