Area Code 978-391 located in AYER, MIDDLESEX, MA, more detail is as below. Place NPA (Numbering Plan Area) : 978 NXX (Local Number Prefix) : 391 City : AYER County : MIDDLESEX State : MA (Massachusetts) NXX Use Type : Landline NXX Intro Version : 2001-10-31 FIPS (Federal Information Processing Standards) : 25017 LATA (Local Access Transport Area) : 128 Rate Center : AYER ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. ZIP Code : 01432 Other Information NPANXX : 978391 Switch CLLI (Common Language Location Identifier) : WRCSMASNDS1 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 : AYER Latitude : 42.5608 Longitude : -71.5900 ‹ previous : 978-390 next › : 978-392 Telephone Number List 978-391-0000 ~ 978-391-9999