Area Code 857-240 located in CAMBRIDGE, MIDDLESEX, MA, more detail is as below. Place NPA (Numbering Plan Area) : 857 NXX (Local Number Prefix) : 240 City : CAMBRIDGE County : MIDDLESEX State : MA (Massachusetts) NXX Use Type : Landline NXX Intro Version : 2/28/2012 FIPS (Federal Information Processing Standards) : 25017 LATA (Local Access Transport Area) : 128 Rate Center : NEWTON ZIP Code Count : 0 ZIP Code Frequency : 0 ZIP Code : 02142 Other Information NPANXX : 857240 MSA CBSA (Core Based Statistical Area) : Boston-Cambridge-Quincy, MA-NH MSA CBSA Code (Core Based Statistical Area) : 14460 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Overlay : L Company : PEERLESS NETWORK OF MASSACHUSETTS, LLC - MA OCN (Operating Company Number) : 268F Coverage Area Name : CAMBRIDGE Latitude : 42.3746 Longitude : -71.0788 ‹ previous : 857-239 next › : 857-241 Telephone Number List 857-240-0000 ~ 857-240-9999