301 Area Code

The 301 area code is serving the western part of Maryland, including Maryland's portion of the Greater Washington, D.C. metro area, portions of southern Maryland, along with rural western Maryland.

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Area Code 301 Location: Maryland

Area code 301 covers the western part of Maryland, encompassing areas within the Greater Washington, D.C. metropolitan region, sections of southern Maryland, and rural western Maryland.

Counties Served by Area Code 301:

  • Allegany County
  • Charles County
  • Garrett County
  • Montgomery County
  • Prince George's County
  • St. Mary's County
  • Washington County
  • Most of Frederick County
  • Western Howard County
  • Slivers of southwestern Carroll County
  • Western Anne Arundel County

Major Cities in the 301 Service Area:

  • Frederick
  • Gaithersburg
  • Rockville
  • Bethesda
  • Silver Spring
  • Germantown
  • Hagerstown
  • Cumberland
  • Waldorf
  • Landover
  • Potomac

Other Cities and Towns:

  • Laurel
  • Mount Airy
  • New Windsor
  • Union Bridge
  • Upper Marlboro

Overlay System

Area code 301 is part of an overlay system with area codes 240 and 227. This means that multiple area codes serve the same geographic region. Area code 301 was established in 1947, area code 240 was added in 1997, and area code 227 was added on June 14, 2023. Ten-digit dialing is required for all calls within this region.

Area Code 301 Location Map

Area Code 301 Location on Maryland Map

Area code 301 is a general purpose code which was placed in service on January 1, 1947.

301 Area Code Prefixes

Our Maryland phone number lookup service will analyze the three-digit prefix of any 301 area code phone number and will show which telecommunications company and rate center it was initially assigned to. This prefix code data may help to determine the U.S. carrier, Maryland geographic region, and local calling area associated with the phone number.

Phone numbers follow the following structure under the North American Numbering Plan:

  • NPA- area code (where the number was originally assigned)
  • NXX - Central office code that locates the specific neighborhood and identifies the service provider
  • XXXX - Subscriber number identifies the individual phone line within that local exchange

Understanding the area code can help you determine if a call is local to your area. However, keep in mind that due to mobile number portability and VoIP services, the caller may be anywhere in the United States, so it’s best to search for the most recent phone number details.

Prefixes by Company

Company Number of Prefixes
VERIZON MARYLAND, INC. 419
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 49
NEW CINGULAR WIRELESS PCS, LLC - DC 42
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 37
SPRINT SPECTRUM, L.P. 26
TELEPORT COMMUNICATIONS AMERICA, LLC - DC 26
LEVEL 3 COMMUNICATIONS, LLC - MD 15
COMCAST IP PHONE, LLC 10
OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6
PAETEC COMMUNICATIONS, INC. - MD 6
BANDWIDTH.COM CLEC, LLC - MD 5
STARPOWER COMMUNICATIONS, LLC - MD 5
USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD 5
SPRINT SPECTRUM, LP - MD 4
CORE COMMUNICATIONS, INC.- MD 3
LEVEL 3 TELECOM OF MARYLAND, LLC - MD 3
CAVALIER TELEPHONE MID-ATLANTIC, LLC - MD 2
ONVOY, LLC - MD 2
TELEPORT COMMUNICATIONS AMERICA, LLC - MD 2
BALTIMORE-WASHINGTON TELEPHONE (BWT) 1
IDT AMERICA, CORP. - MD 1
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 1
MOUNTAIN COMMUNICATIONS, LLC DBA PROCOM - MD 1
ONVOY SPECTRUM, LLC 1
QUANTUM TELECOMMUNICATIONS, INC. - MD 1
US LEC OF MARYLAND, INC. 1
USA MOBILITY WIRELESS, INC. 1
VDL, INC. DBA GLOBAL TELECOM BROKERS - MD 1
XO MARYLAND, LLC 1
YMAX COMMUNICATIONS CORP. - MD 1

Carrier names have been updated from their original FCC assignments to reflect current companies following mergers, acquisitions, and rebranding. Updates were determined using AI-assisted research and may not be accurate or reflect up to date changes. This data is provided without warranties of accuracy or completeness.

Prefixes by Rate Center

Rate Center Number of Prefixes
WSHNGTNZN3 103
WSHNGTNZN2 78
WSNGTNZN10 47
WSNG236Z13 38
WSHNGTNZN4 37
FREDERICK 35
GAITHERSBG 32
WSHNGTNZN5 29
WSNGTNZN11 27
LAUREL236 22
WALDORF 22
WSNG236Z14 20
HAGERSTOWN 19
WSHNGTNZN6 18
CUMBERLAND 13
WSNGTNZN12 13
LXTNPKGRML 9
ASHTON236 8
LEONARDTN 8
OAKLAND 7
WSNG236Z15 7
DAMASCS236 6
WSNG238Z14 6
INDIANHEAD 5
MYERSVILLE 5
WSNGTNZN16 5
BRANDYWINE 4
DAMASCS240 4
KEEDYSVL 3
LA PLATA 3
LAUREL238 3
MECHANCSVL 3
ASHTON238 2
BRUNSWICK 2
BUCKEYSTN 2
FRIENDSVL 2
FROSTBURG 2
MOUNT AIRY 2
NEW MARKET 2
WALKERSVL 2
WSNG238Z15 2
BITTINGER 1
CLEAR SPG 1
EMMITSBURG 1
FLINTSTONE 1
GRANTSVL 1
HANCOCK 1
HIGHFIELD 1
HUGHESVL 1
KITZMILLER 1
LONACONING 1
MIDDLETOWN 1
MT SAVAGE 1
NANJEMOY 1
POOLESVL 1
RIDGE 1
SMITHSBURG 1
THURMONT 1
TOMPKINSVL 1
WESTERNPT 1
WILLIAMSPT 1
WSNG238Z13 1

Other Maryland Area Codes

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