Area Code 301-337 located in GAITHERSBURG, MONTGOMERY, MD, more detail is as below. Place NPA (Numbering Plan Area) : 301 NXX (Local Number Prefix) : 337 City : GAITHERSBURG County : MONTGOMERY State : MD (Maryland) NXX Use Type : Landline NXX Intro Version : 1995-07-04 FIPS (Federal Information Processing Standards) : 24031 LATA (Local Access Transport Area) : 236 Rate Center : GAITHERSBG ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 20882 Other Information NPANXX : 301337 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 Company : MCI WORLDCOM COMMUNICATIONS, INC. - MD OCN (Operating Company Number) : 7228 Coverage Area Name : GAITHERSBURG Latitude : 39.1431 Longitude : -77.2031 ‹ previous : 301-336 next › : 301-338 Telephone Number List 301-337-0000 ~ 301-337-9999