857 Area CodeThe 857 area code is found in the state of Massachusetts, and spans 4 different Counties. Listed below are the 4 Counties that reside inside of the 857 area code. Included under the Counties are the cities within the given County.
Bristol County Massachusetts
Middlesex County Massachusetts
Belmont, Cambridge, Chestnut Hill, Everett, Malden, Newton, Newtonville, Somerville, Watertown, West Newton
Norfolk County Massachusetts
Brookline, Needham, Quincy
Suffolk County Massachusetts
Boston, Brighton, Charlestown, Chelsea, Dorchester, Hyde Park, Jamaica Plain, Roxbury Crossing, Winthrop