Area Code 240-341 located in FREDERICK, FREDERICK, MD, more detail is as below. Place NPA (Numbering Plan Area) : 240 NXX (Local Number Prefix) : 341 City : FREDERICK County : FREDERICK State : MD (Maryland) NXX Use Type : Landline NXX Intro Version : 10/27/2008 FIPS (Federal Information Processing Standards) : 24021 LATA (Local Access Transport Area) : 240 Rate Center : BUCKEYSTN ZIP Code Count : 0 ZIP Code Frequency : 0 ZIP Code : 21704 Other Information NPANXX : 240341 County Population : 0 MSA CBSA (Core Based Statistical Area) : Washington-Arlington-Alexandria, DC-VA-MD-WV MSA CBSA Code (Core Based Statistical Area) : 47900 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Overlay : L Company : MCI WORLDCOM COMMUNICATIONS, INC. - MD OCN (Operating Company Number) : 7228 Coverage Area Name : ADAMSTOWN Latitude : 39.3325 Longitude : -77.4353 ‹ previous : 240-340 next › : 240-342 Telephone Number List 240-341-0000 ~ 240-341-9999