Area Code 240-310 located in HAGERSTOWN, WASHINGTON, MD, more detail is as below. Place NPA (Numbering Plan Area) : 240 NXX (Local Number Prefix) : 310 City : HAGERSTOWN County : WASHINGTON State : MD (Maryland) NXX Use Type : Wireless NXX Intro Version : 1999-02-27 FIPS (Federal Information Processing Standards) : 24043 LATA (Local Access Transport Area) : 240 Rate Center : HAGERSTOWN ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. ZIP Code : 21742 Other Information NPANXX : 240310 County Population : 0 Switch CLLI (Common Language Location Identifier) : CMLDMDCM5MD MSA CBSA (Core Based Statistical Area) : Hagerstown-Martinsburg, MD-WV MSA CBSA Code (Core Based Statistical Area) : 25180 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Overlay : L Company : USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD OCN (Operating Company Number) : 4720 Coverage Area Name : HAGERSTOWN Latitude : 39.6425 Longitude : -77.7281 ‹ previous : 240-309 next › : 240-312 Telephone Number List 240-310-0000 ~ 240-310-9999