Area Code 301-212 located in DERWOOD, MONTGOMERY, MD, more detail is as below. Place NPA (Numbering Plan Area) : 301 NXX (Local Number Prefix) : 212 City : DERWOOD County : MONTGOMERY State : MD (Maryland) NXX Use Type : Landline NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 24031 LATA (Local Access Transport Area) : 236 Rate Center : WSNGTNZN10 ZIP Code Count : 19 ZIP Code Frequency : 6 ZIP Code : 20855 Other Information NPANXX : 301212 County Population : 0 Switch CLLI (Common Language Location Identifier) : GTBGMDGBDS0 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 Company : VERIZON MARYLAND, INC. OCN (Operating Company Number) : 9212 Coverage Area Name : GAITHERSBURG Latitude : 39.1431 Longitude : -77.2031 ‹ previous : 301-212 next › : 301-212 Telephone Number List 301-212-0000 ~ 301-212-9999