Area Code 617-391 located in SOMERVILLE, MIDDLESEX, MA, more detail is as below. Place NPA (Numbering Plan Area) : 617 NXX (Local Number Prefix) : 391 City : SOMERVILLE County : MIDDLESEX State : MA (Massachusetts) NXX Use Type : Wireless NXX Intro Version : 1999-07-22 FIPS (Federal Information Processing Standards) : 25017 LATA (Local Access Transport Area) : 128 Rate Center : CAMBRIDGE ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 02144 Other Information NPANXX : 617391 Switch CLLI (Common Language Location Identifier) : WOBNMAPJCM0 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 Company : CTC COMMUNICATIONS CORP. - MA OCN (Operating Company Number) : 3370 Coverage Area Name : BOSTON Latitude : 42.3568 Longitude : -71.0588 ‹ previous : 617-390 next › : 617-392 Telephone Number List 617-391-0000 ~ 617-391-9999