Area Code 857 History:
Area code 857 was put into service. Area code 857 is an overlay of area code 617.
Counties in Massachusetts within area code 857 include:
Middlesex County, Norfolk County, and Suffolk County.
Major cities or places in Massachusetts within area code 857 include:
Area codes 617 and 857 serve an area of east central Massachusetts, including Boston and the close suburbs of Boston. Some of the larger communities served by area codes 617 and 857, include Belmont, Brookline, Cambridge, Chelsea, Everett, Milton, Newton, Quincy, Somerville, Watertown and Winthrop in addition to many smaller communities within the area codes 617 and 857 service area.