301 area code
Area code 301 is a North American telephone area code serving the western part of the U.S. state of Maryland, including the city of Frederick and the state capital of Annapolis. It also covers the majority of Montgomery County, Prince George's County, and a small portion of Charles County.
In addition to area code 301, the overlay code 240 also serves the same region. This overlay was introduced to ensure a sufficient number of available phone numbers due to increased demand for telephone lines and devices. When you make a call within the area covered by both 301 and 240, you must dial the full ten-digit number, including the area code, even for local calls.
| State | Maryland |
| Major City | Germantown |
| Timezone | Eastern Time (ET) |
What time zone is area code 301?
The 301 area code is primarily located in the Eastern Time Zone (ET) in the United States. Eastern Time is typically UTC-5:00 during Standard Time and UTC-4:00 during Daylight Saving Time (DST). DST is observed in most parts of the Eastern Time Zone, where the clocks are set forward by one hour in the spring and set back by one hour in the fall to make better use of natural daylight.
Note: Not all areas within the 301 area code may observe DST, so it's always a good idea to check with local sources or official announcements for the current time and whether DST is in effect.
History
This area code was one of the original area codes established in 1947 when the North American Numbering Plan (NANP) was introduced. It was one of the first area codes to be created and served the entire state of Maryland until it was split in 1991, with the eastern part of Maryland receiving the new area code 410.
Nearby Area Codes to 301
The 301 area code in Maryland has several nearby area codes, which include:
| Area Code | Location | History and Details |
|---|---|---|
| 202 | District of Columbia | Covers the District of Columbia. |
| 223 | Lancaster, PA | Overlay area code for 717, covers the same geographic area. |
| 240 | Germantown, MD | Overlay area code for 301, covers the same geographic area. |
| 301 | Western Maryland | Covers the western part of Maryland. |
| 304 | West Virginia | Covers the entire state of West Virginia. |
| 410 | Baltimore, MD | Covers the eastern part of Maryland, including Baltimore. |
| 434 | Lynchburg, VA | Covers the Lynchburg area in Virginia. |
| 484 | Allentown, PA | Overlay area code for 610, covers the same geographic area. |
| 540 | Roanoke, VA | Covers the Roanoke area in Virginia. |
| 571 | Arlington, VA | Overlay area code for 703, covers the same geographic area. |
| 582 | Erie, PA | Overlay area code for 814, covers the same geographic area. |
| 724 | New Castle, PA | Covers the New Castle area in Pennsylvania. |
| 757 | Virginia Beach, VA | Covers the Virginia Beach area in Virginia. |
| 804 | Richmond, VA | Covers the Richmond area in Virginia. |
| 878 | Pittsburgh, PA | Overlay area code for 412, covers the same geographic area. |
Counties in Area Code 301
Please note that the list of counties served by area codes can change over time due to population growth and the need for additional telephone numbers.
| County | Total Population | % of 301 | % of County | Details/History |
|---|---|---|---|---|
| Montgomery, MD | 1,071,777 | 11% | 100% | Montgomery County is the most populous county in Maryland and is known for its diverse communities and strong economy. It is home to many cultural attractions, including the National Institutes of Health (NIH) and the National Museum of Health and Medicine. |
| Prince George's, MD | 963,420 | 10% | 100% | Prince George's County is located in the suburbs of Washington, D.C. It is known for its rich history and cultural diversity. The county is home to the University of Maryland and several historic sites, including the Riversdale Mansion. |
| Frederick, MD | 253,385 | 14% | 100% | Frederick County is known for its scenic beauty and historical sites. It is home to the city of Frederick, which has a vibrant downtown area with shops, restaurants, and cultural attractions. |
| Washington, MD | 157,430 | 10% | 100% | Washington County, located in western Maryland, is known for its rich history and outdoor recreational opportunities. It is home to Hagerstown, the county seat, and Antietam National Battlefield. |
| Charles, MD | 156,551 | 13% | 100% | Charles County is situated in southern Maryland and offers a mix of rural and suburban living. It has a growing economy and is known for its waterfront communities along the Potomac River. |
| St. Mary's, MD | 115,151 | 16% | 100% | St. Mary's County is located in southern Maryland and is known for its naval and aerospace industry. It has a rich history, including the site of Maryland's first colonial landing. |
| Allegany, MD | 85,087 | 9% | 100% | Allegany County is in western Maryland and offers scenic mountain views and outdoor recreation opportunities. It has a strong emphasis on education and is home to Frostburg State University. |
| Howard, MD | 307,085 | 1% | 24% | Howard County is known for its high standard of living and excellent schools. It is part of the Baltimore-Washington metropolitan area and has a strong economy. |
| Anne Arundel, MD | 577,656 | 1% | 7% | Anne Arundel County is known for its waterfront communities along the Chesapeake Bay. It is home to the state capital, Annapolis, and the U.S. Naval Academy. |
| Garrett, MD | 35,097 | 14% | 100% | Garrett County is in western Maryland and offers picturesque landscapes, including Deep Creek Lake. It is known for outdoor activities such as hiking, skiing, and boating. |
| Calvert, MD | 98,737 | 1% | 8% | Calvert County is located on the Chesapeake Bay and is known for its natural beauty and historic sites. It is a popular destination for boating and water-related activities. |
| Carroll, MD | 167,656 | 4% | 100% | Carroll County is located in northern Maryland and is known for its rural charm and historic towns. It has a strong agricultural heritage and is home to the Carroll County Farm Museum. |
| Harford, MD | 255,441 | 3% | 100% | Harford County is in northeastern Maryland and offers a mix of suburban and rural living. It has a strong education system and is known for its historic sites and natural beauty along the Susquehanna River. |
Cities in Area Code 301
Area code 301 primarily serves the state of Maryland in the United States. These cities within area code 301 offer a wide range of experiences, from the urban excitement of Baltimore to the more tranquil and suburban settings found in other parts of the region.
Here are some of the cities and areas within this area code:
| City | Total Population | Details |
|---|---|---|
| Rockville | Approx. 68,000 | Rockville is a major city in Montgomery County known for its diverse population and vibrant downtown area. It's a hub for biotechnology and cybersecurity industries. |
| Gaithersburg | Approx. 70,000 | Gaithersburg is a city in Montgomery County known for its strong economy and cultural diversity. It hosts the annual Gaithersburg Book Festival and various community events. |
| Bethesda | Approx. 63,000 | Bethesda, located in Montgomery County, is known for its affluent neighborhoods, medical research institutions, and the Walter Reed National Military Medical Center. |
| Frederick | Approx. 74,000 | Frederick is a city in Frederick County with a historic downtown area, cultural attractions, and a growing arts scene. It's often called "Fredneck." |
| Hagerstown | Approx. 40,000 | Hagerstown is the largest city in western Maryland, located in Washington County. It has a rich history and is known for its arts and culture. |
| Greenbelt | Approx. 23,000 | Greenbelt is a planned community in Prince George's County known for its focus on green living and sustainability. It's home to NASA's Goddard Space Flight Center. |
| Laurel | Approx. 26,000 | Laurel is a city that straddles the border of Prince George's County and Howard County. It's known for its historic district and vibrant community. |
| College Park | Approx. 32,000 | College Park is home to the University of Maryland and is located in Prince George's County. It's known for its academic institutions and research facilities. |
| Bowie | Approx. 58,000 | Bowie is a city in Prince George's County known for its family-friendly neighborhoods and recreational facilities. It's one of the largest cities in Maryland. |
| Waldorf | Approx. 71,000 | Waldorf is located in Charles County and is one of the fastest-growing areas in Maryland. It offers a mix of suburban and rural living. |
| Cumberland | Approx. 19,000 | Cumberland is a city in Allegany County known for its scenic beauty and outdoor activities, including the C&O Canal and the Western Maryland Scenic Railroad. |
| Annapolis (Partial) | Approx. 40,000 | Annapolis is the capital of Maryland and is located in Anne Arundel County. It's known for its historic district, naval academy, and maritime heritage. |
| Hampstead | Approx. 6,400 | Hampstead is a town in Carroll County known for its small-town charm and community events, including the Hampstead Day festival. |
| Morningside | Approx. 2,000 | Morningside is a town in Prince George's County known for its residential neighborhoods and proximity to Washington, D.C. |
| Sykesville | Approx. 4,500 | Sykesville is a town in Carroll County known for its historic downtown and community events like the Sykesville Art & Wine Festival. |
| North Beach | Approx. 2,000 | North Beach is a town in Calvert County known for its beachfront area, boardwalk, and family-friendly atmosphere. |
| Cheverly | Approx. 6,500 | Cheverly is a town in Prince George's County known for its tree-lined streets and close-knit community. |
| Williamsport | Approx. 2,500 | Williamsport is a town in Washington County known for its historic C&O Canal and scenic riverfront. |
| Edmonston | Approx. 1,500 | Edmonston is a town in Prince George's County known for its environmental initiatives and community gardens. |
| Seat Pleasant | Approx. 4,700 | Seat Pleasant is a town in Prince George's County known for its small-town feel and community events. |
| Myersville | Approx. 1,900 | Myersville is a town in Frederick County known for its rural charm and scenic landscapes. |
| Taneytown | Approx. 7,000 | Taneytown is a town in Carroll County known for its historic district and community events like the Taneytown Carnival. |
| Berlin | Approx. 4,500 | Berlin is a town in Worcester County known for its charming downtown, historic homes, and proximity to Ocean City. |
| Garrett Park | Approx. 1,000 | Garrett Park is a town in Montgomery County known for its tree-lined streets and sense of community. |
| Emmitsburg | Approx. 3,000 | Emmitsburg is a town in Frederick County known for its historic sites, including the National Shrine of Saint Elizabeth Ann Seton. |
| Kensington | Approx. 2,500 | Kensington is a town in Montgomery County known for its historic district and community events like the Labor Day Parade. |
| Brentwood | Approx. 3,000 | Brentwood is a town in Prince George's County known for its residential neighborhoods and sense of community. |
| Keedysville | Approx. 1,200 | Keedysville is a town in Washington County known for its historic sites and scenic beauty. |
| Capitol Heights | Approx. 4,400 | Capitol Heights is a town in Prince George's County known for its proximity to Washington, D.C., and its affordable housing options. |
| Eagle Harbor | Approx. 60 | Eagle Harbor is a small town in Prince George's County located along the Patuxent River. |
| Laytonsville | Approx. 400 | Laytonsville is a town in Montgomery County known for its rural character and historic district. |
| Rock Hall | Approx. 1,300 | Rock Hall is a town in Kent County known for its waterfront location along the Chesapeake Bay. |
| New Windsor | Approx. 1,400 | New Windsor is a town in Carroll County known for its historic district and community events like the New Windsor Fireman's Carnival. |
| University Park | Approx. 2,700 | University Park is a town in Prince George's County known for its tree-lined streets and proximity to the University of Maryland. |
| Woodsboro | Approx. 1,000 | Woodsboro is a town in Frederick County known for its small-town atmosphere and historic buildings. |
| Glen Echo | Approx. 300 | Glen Echo is a town in Montgomery County known for its arts community and the Glen Echo Park. |
| Chevy Chase | Approx. 3,000 | Chevy Chase is a town in Montgomery County known for its upscale residential areas and proximity to Washington, D.C. |
| Union Bridge | Approx. 1,000 | Union Bridge is a town in Carroll County known for its small-town charm and historic Main Street. |
| Poolesville | Approx. 5,000 | Poolesville is a town in Montgomery County known for its rural character, strong community, and outdoor recreational opportunities. |
| Church Hill | Approx. 700 | Church Hill is a town in Queen Anne's County known for its historic district and community events like the Church Hill Theatre. |
| Indian Head | Approx. 4,000 | Indian Head is a town in Charles County located along the Potomac River. It's known for its naval support facility. |
| Trappe | Approx. 1,100 | Trappe is a town in Talbot County known for its historic charm and community events like the Christmas in Trappe celebration. |
| Goldsboro | Approx. 300 | Goldsboro is a town in Caroline County known for its agricultural heritage and close-knit community. |
| Ridgely | Approx. 1,800 | Ridgely is a town in Caroline County known for its annual Strawberry Festival and agricultural traditions. |
| Federalsburg | Approx. 2,700 | Federalsburg is a town in Caroline County known for its annual Whistlestop Festival and historic district. |
| Barnesville | Approx. 200 | Barnesville is a small town in Montgomery County known for its rural character and community events like the Barnesville BBQ Bash. |
| Glenarden | Approx. 6,000 | Glenarden is a town in Prince George's County known for its residential neighborhoods and proximity to major transportation routes. |
| New Market | Approx. 700 | New Market is a town in Frederick County known for its historic district and annual festivals like the New Market Days celebration. |
| Preston | Approx. 800 | Preston is a town in Caroline County known for its agricultural heritage and community events. |
| Morningside | Approx. 2,000 | Morningside is a town in Prince George's County known for its residential neighborhoods and proximity to Washington, D.C. |
| Keedysville | Approx. 1,200 | Keedysville is a town in Washington County known for its historic sites and scenic beauty. |
| Cheverly | Approx. 6,500 | Cheverly is a town in Prince George's County known for its tree-lined streets and close-knit community. |
| Bowie | Approx. 58,000 | Bowie is a city in Prince George's County known for its family-friendly neighborhoods and recreational facilities. It's one of the largest cities in Maryland. |
| Waldorf | Approx. 71,000 | Waldorf is located in Charles County and is one of the fastest-growing areas in Maryland. It offers a mix of suburban and rural living. |
| Cumberland | Approx. 19,000 | Cumberland is a city in Allegany County known for its scenic beauty and outdoor activities, including the C&O Canal and the Western Maryland Scenic Railroad. |
| Annapolis (Partial) | Approx. 40,000 | Annapolis is the capital of Maryland and is located in Anne Arundel County. It's known for its historic district, naval academy, and maritime heritage. |
| Hampstead | Approx. 6,400 | Hampstead is a town in Carroll County known for its small-town charm and community events, including the Hampstead Day festival. |
| Morningside | Approx. 2,000 | Morningside is a town in Prince George's County known for its residential neighborhoods and proximity to Washington, D.C. |
| Sykesville | Approx. 4,500 | Sykesville is a town in Carroll County known for its historic downtown and community events like the Sykesville Art & Wine Festival. |
| North Beach | Approx. 2,000 | North Beach is a town in Calvert County known for its beachfront area, boardwalk, and family-friendly atmosphere. |
| Cheverly | Approx. 6,500 | Cheverly is a town in Prince George's County known for its tree-lined streets and close-knit community. |
| Williamsport | Approx. 2,500 | Williamsport is a town in Washington County known for its historic C&O Canal and scenic riverfront. |
| Edmonston | Approx. 1,500 | Edmonston is a town in Prince George's County known for its environmental initiatives and community gardens. |
| Seat Pleasant | Approx. 4,700 | Seat Pleasant is a town in Prince George's County known for its small-town feel and community events. |
| Myersville | Approx. 1,900 | Myersville is a town in Frederick County known for its rural charm and scenic landscapes. |
| Taneytown | Approx. 7,000 | Taneytown is a town in Carroll County known for its historic district and community events like the Taneytown Carnival. |
| Berlin | Approx. 4,500 | Berlin is a town in Worcester County known for its charming downtown, historic homes, and proximity to Ocean City. |
| Federalsburg | Approx. 2,700 | Federalsburg is a town in Caroline County known for its annual Whistlestop Festival and historic district. |
| Barnesville | Approx. 200 | Barnesville is a small town in Montgomery County known for its rural character and community events like the Barnesville BBQ Bash. |
| Glenarden | Approx. 6,000 | Glenarden is a town in Prince George's County known for its residential neighborhoods and proximity to major transportation routes. |
| New Market | Approx. 700 | New Market is a town in Frederick County known for its historic district and annual festivals like the New Market Days celebration. |
| Preston | Approx. 800 | Preston is a town in Caroline County known for its agricultural heritage and community events. |
| Goldsboro | Approx. 300 | Goldsboro is a town in Caroline County known for its agricultural heritage and close-knit community. |
| Ridgely | Approx. 1,800 | Ridgely is a town in Caroline County known for its annual Strawberry Festival and agricultural traditions. |
| Chevy Chase | Approx. 3,000 | Chevy Chase is a town in Montgomery County known for its upscale residential areas and proximity to Washington, D.C. |
| Union Bridge | Approx. 1,000 | Union Bridge is a town in Carroll County known for its small-town charm and historic Main Street. |
| Poolesville | Approx. 5,000 | Poolesville is a town in Montgomery County known for its rural character, strong community, and outdoor recreational opportunities. |
| Church Hill | Approx. 700 | Church Hill is a town in Queen Anne's County known for its historic district and community events like the Church Hill Theatre. |
| Indian Head | Approx. 4,000 | Indian Head is a town in Charles County located along the Potomac River. It's known for its naval support facility. |
Largest telephone carriers in area code 301
This table provides a quick overview of nearby area codes, their locations, and some historical context for each.
| Carrier | Landline Market Share | Wireless Market Share |
|---|---|---|
| Verizon | 58% | 6% |
| Teleport America | 3% | - |
| Mci Worldcom | 3% | - |
| Mcimetro Access Transmission Services | 2% | - |
| Level 3 | 2% | - |
| Comcast Phone Of Northern | 2% | - |
| AT&T Local | 1% | - |
| Other | 6% | 15% |
| Verizon Wireless | - | 6% |
| Cingular | - | 5% |
| Sprint | - | 4% |
| Usa Mobility Wireless | - | 2% |
| Omnipoint Cap Operations | - | 1% |
| United States Cel Md | - | 1% |
| Other | - | 15% |
Prefixes in Area Code 301
Below is the list of some of Prefixes in area code 301
| Prefix | Usage | Primary City | Carrier | Introduction Date |
|---|---|---|---|---|
| (301) 200- | Landline | Indian Head | Bandwidth.com | 02/24/2011 |
| (301) 202- | Wireless | Chevy Chase | Cingular Wireless | 12/19/2008 |
| (301) 203- | Landline | Fort Washington | 02/04/1994 | |
| (301) 204- | Wireless | Bethesda | Cingular Wireless | 04/15/1996 |
| (301) 205- | Landline | Edgewater | 07/06/1997 | |
| (301) 206- | Landline | Laurel | 02/04/1994 | |
| (301) 207- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 208- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 209- | Landline | Hyattsville | 02/04/1994 | |
| (301) 210- | Landline | Beltsville | 02/04/1994 | |
| (301) 212- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 213- | Wireless | Beltsville | Sprint | 07/06/1997 |
| (301) 214- | Landline | Rockville | 02/04/1994 | |
| (301) 215- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 216- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 217- | Landline | Rockville | 02/04/1994 | |
| (301) 218- | Landline | Bowie | 01/10/1996 | |
| (301) 219- | Wireless | Bethesda | Cingular Wireless | 07/04/1995 |
| (301) 220- | Landline | Greenbelt | 02/04/1994 | |
| (301) 221- | Wireless | Bethesda | Cingular Wireless | 09/11/1994 |
| (301) 222- | Landline | Bethesda | Cavalier Telephone Mid-atlantic | 10/11/1997 |
| (301) 223- | Landline | Williamsport | 02/04/1994 | |
| (301) 224- | Wireless | Chevy Chase | USA Mobility Wireless | 04/15/1996 |
| (301) 225- | Landline | Glenn Dale | Teleport Comms America | 05/21/2009 |
| (301) 226- | Landline | Hyattsville | 07/01/1996 | |
| (301) 227- | Landline | Glen Echo | 02/04/1994 | |
| (301) 228- | Landline | Frederick | 07/06/1997 | |
| (301) 229- | Landline | Glen Echo | 02/04/1994 | |
| (301) 230- | Landline | Rockville | 02/04/1994 | |
| (301) 231- | Landline | Rockville | 02/04/1994 | |
| (301) 232- | Landline | Sandy Spring | Mci Worldcom Comms | 01/11/1997 |
| (301) 233- | Wireless | Silver Spring | Verizon Wireless | 04/01/1997 |
| (301) 234- | Landline | Fort Washington | 01/11/1997 | |
| (301) 235- | Landline | Clinton | MCI Metro ATS | 01/11/1997 |
| (301) 236- | Landline | Silver Spring | 02/04/1994 | |
| (301) 237- | Wireless | Beltsville | Sprint | 04/01/1997 |
| (301) 238- | Landline | Temple Hills | 02/04/1994 | |
| (301) 239- | Wireless | Hyattsville | 02/11/1995 | |
| (301) 240- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 241- | Landline | Highfield | 01/10/1996 | |
| (301) 242- | Landline | Brandywine | MCI Metro ATS | 01/11/1997 |
| (301) 243- | Landline | Bethesda | 07/20/2006 | |
| (301) 244- | Landline | Rockville | Telcove Operations | 01/11/1997 |
| (301) 245- | Landline | Bittinger | 02/04/1994 | |
| (301) 246- | Landline | Nanjemoy | 02/04/1994 | |
| (301) 247- | Wireless | Leonardtown | Cingular Wireless | 01/10/1996 |
| (301) 248- | Landline | Fort Washington | 02/04/1994 | |
| (301) 249- | Landline | Bowie | 02/04/1994 | |
| (301) 250- | Landline | Rockville | Mci Worldcom Comms | 01/11/1997 |
| (301) 251- | Landline | Rockville | 02/04/1994 | |
| (301) 252- | Wireless | Gaithersburg | Sprint | 01/10/1996 |
| (301) 253- | Landline | Damascus | 02/04/1994 | |
| (301) 254- | Wireless | Beltsville | Sprint | 01/10/1996 |
| (301) 255- | Landline | Rockville | 01/11/1997 | |
| (301) 256- | Landline | Laurel | Mci Worldcom Comms | 01/11/1997 |
| (301) 257- | Wireless | Beltsville | Sprint | 10/11/1997 |
| (301) 258- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 259- | Landline | Issue | 02/04/1994 | |
| (301) 260- | Landline | Ashton | 07/06/1997 | |
| (301) 261- | Landline | Glenn Dale | 02/04/1994 | |
| (301) 262- | Landline | Bowie | 02/04/1994 | |
| (301) 263- | Landline | Glen Echo | 04/01/1997 | |
| (301) 264- | Landline | Mount Savage | 02/04/1994 | |
| (301) 265- | Landline | Fort Washington | 01/11/1997 | |
| (301) 266- | Wireless | Waldorf | Cingular Wireless | 01/11/1997 |
| (301) 267- | Wireless | Greenbelt | Sprint | 10/04/2011 |
| (301) 268- | Wireless | Cumberland | Uscoc Of Cumberland DBA United States Cel Md | 07/06/1997 |
| (301) 270- | Landline | Hyattsville | 02/04/1994 | |
| (301) 271- | Landline | Thurmont | 02/04/1994 | |
| (301) 272- | Landline | Rockville | Mci Worldcom Comms | 01/11/1997 |
| (301) 273- | Landline | Silver Spring | Mci Worldcom Comms | 01/11/1997 |
| (301) 274- | Landline | Hughesville | 02/04/1994 | |
| (301) 275- | Wireless | Bethesda | Cingular Wireless | 02/11/1995 |
| (301) 276- | Landline | Hyattsville | Mci Worldcom Comms | 01/11/1997 |
| (301) 277- | Landline | Hyattsville | 02/04/1994 | |
| (301) 278- | Landline | Mount Rainier | Mci Worldcom Comms | 01/11/1997 |
| (301) 279- | Landline | Rockville | 02/04/1994 | |
| (301) 280- | Landline | Chevy Chase | 10/11/1997 | |
| (301) 281- | Landline | Oxon Hill | Mci Worldcom Comms | 01/11/1997 |
| (301) 282- | Landline | Silver Spring | 07/04/1995 | |
| (301) 283- | Landline | Bryans Road | 02/04/1994 | |
| (301) 284- | Landline | Rockville | Mci Worldcom Comms | 01/11/1997 |
| (301) 285- | Wireless | Silver Spring | 07/04/1995 | |
| (301) 286- | Landline | Greenbelt | 02/04/1994 | |
| (301) 287- | Landline | Rockville | Mci Worldcom Comms | 01/11/1997 |
| (301) 288- | Landline | Rockville | Mci Worldcom Comms | 01/10/1996 |
| (301) 289- | Landline | College Park | Mci Worldcom Comms | 01/11/1997 |
| (301) 290- | Landline | Mechanicsville | 07/06/1997 | |
| (301) 291- | Landline | Mount Rainier | Mci Worldcom Comms | 01/11/1997 |
| (301) 292- | Landline | Fort Washington | 02/04/1994 | |
| (301) 293- | Landline | Myersville | 02/04/1994 | |
| (301) 294- | Landline | Rockville | 02/04/1994 | |
| (301) 295- | Landline | Rockville | 02/04/1994 | |
| (301) 296- | Landline | Rockville | Mci Worldcom Comms | 07/04/1995 |
| (301) 297- | Landline | Fort Washington | 02/04/1994 | |
| (301) 298- | Landline | Upper Marlboro | MCI Metro ATS | 04/01/1997 |
| (301) 299- | Landline | Bethesda | 02/04/1994 | |
| (301) 300- | Wireless | Bethesda | Verizon Wireless | 03/30/2007 |
| (301) 302- | Landline | Hagerstown | Sprint | 10/05/2004 |
| (301) 303- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 304- | Landline | Frederick | Comcast Phone Of Northern Maryland | 03/06/2007 |
| (301) 305- | Wireless | Frederick | Sprint | 04/15/1996 |
| (301) 306- | Landline | Lanham | 02/04/1994 | |
| (301) 307- | Landline | College Park | 07/01/1996 | |
| (301) 308- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 309- | Landline | Rockville | 02/04/1994 | |
| (301) 310- | Landline | Columbia | 07/01/1996 | |
| (301) 312- | Wireless | Oxon Hill | Cingular Wireless | 10/11/1997 |
| (301) 313- | Landline | Greenbelt | 10/11/1997 | |
| (301) 314- | Landline | Hyattsville | Paetec Comms | 02/04/1994 |
| (301) 315- | Landline | Rockville | 07/01/1996 | |
| (301) 316- | Landline | Temple Hills | 07/06/1997 | |
| (301) 317- | Landline | Laurel | 02/04/1994 | |
| (301) 318- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 319- | Landline | Rockville | 07/01/1996 | |
| (301) 320- | Landline | Glen Echo | 02/04/1994 | |
| (301) 321- | Landline | Rockville | Telcove Operations | 07/06/1997 |
| (301) 322- | Landline | Hyattsville | 02/04/1994 | |
| (301) 323- | Landline | Laurel | Tw Telecom | 07/06/1997 |
| (301) 324- | Landline | Capitol Heights | 07/04/1995 | |
| (301) 325- | Wireless | Silver Spring | Verizon Wireless | 07/04/1995 |
| (301) 326- | Wireless | Silver Spring | Omnipoint Comms Cap Operations | 10/11/1997 |
| (301) 327- | Landline | Upper Marlboro | Comcast Phone Of Northern Maryland | 03/09/2006 |
| (301) 328- | Landline | Silver Spring | Comcast Phone Of Northern Maryland | 06/21/2006 |
| (301) 329- | Wireless | Greenbelt | Cavalier Telephone Mid-atlantic | 09/20/2011 |
| (301) 330- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 331- | Wireless | Hagerstown | Cingular Wireless | 02/04/1994 |
| (301) 332- | Wireless | Silver Spring | Cingular Wireless | 10/15/1996 |
| (301) 333- | Landline | Capitol Heights | 01/11/1997 | |
| (301) 334- | Landline | Oakland | 02/04/1994 | |
| (301) 335- | Wireless | Bethesda | Cingular Wireless | 09/11/1994 |
| (301) 336- | Landline | Capitol Heights | 02/04/1994 | |
| (301) 337- | Landline | Gaithersburg | Mci Worldcom Comms | 07/04/1995 |
| (301) 338- | Landline | Cumberland | Idt America Corp | 01/31/2006 |
| (301) 339- | Landline | Rockville | Cavalier Telephone Mid-atlantic | 10/11/1997 |
| (301) 340- | Landline | Rockville | 02/04/1994 | |
| (301) 341- | Landline | Hyattsville | 02/04/1994 | |
| (301) 342- | Landline | Patuxent River | 01/10/1996 | |
| (301) 343- | Wireless | Capitol Heights | Sprint | 02/11/1995 |
| (301) 344- | Landline | Greenbelt | 02/04/1994 | |
| (301) 345- | Landline | Greenbelt | 02/04/1994 | |
| (301) 346- | Wireless | Silver Spring | Cingular Wireless | 10/11/1997 |
| (301) 347- | Landline | Chevy Chase | 10/15/1996 | |
| (301) 348- | Landline | Kensington | Mci Worldcom Comms | 07/04/1995 |
| (301) 349- | Landline | Poolesville | 02/04/1994 | |
| (301) 350- | Landline | Capitol Heights | 02/04/1994 | |
| (301) 351- | Wireless | Silver Spring | Verizon Wireless | 07/04/1995 |
| (301) 352- | Landline | Bowie | 09/11/1994 | |
| (301) 353- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 354- | Landline | Rockville | Teleport Comms America | 01/10/1996 |
| (301) 355- | Landline | Gaithersburg | 12/08/2005 | |
| (301) 356- | Landline | Laurel | Vdl DBA Global Telecom Brokers | 08/17/2004 |
| (301) 357- | Wireless | Mount Rainier | Verizon Wireless | 10/12/2006 |
| (301) 358- | Landline | Upper Marlboro | Level 3 Comms | 10/11/1997 |
| (301) 359- | Landline | Westernport | 01/10/1996 | |
| (301) 360- | Landline | Frederick | 01/25/1998 | |
| (301) 361- | Landline | Laurel | Tw Telecom | 10/11/1997 |
| (301) 362- | Landline | Laurel | 10/11/1997 | |
| (301) 363- | Landline | Damascus | Level 3 Comms | 08/16/2006 |
| (301) 364- | Landline | Hyattsville | Mci Worldcom Comms | 07/04/1995 |
| (301) 365- | Landline | Bethesda | 02/04/1994 | |
| (301) 366- | Wireless | Gaithersburg | Sprint | 10/11/1997 |
| (301) 367- | Wireless | Silver Spring | Verizon Wireless | 02/11/1995 |
| (301) 368- | Landline | Damascus | 01/25/1998 | |
| (301) 369- | Landline | Laurel | 02/04/1994 | |
| (301) 370- | Wireless | Gaithersburg | Sprint | 05/18/1998 |
| (301) 371- | Landline | Middletown | 02/04/1994 | |
| (301) 372- | Landline | Brandywine | 02/04/1994 | |
| (301) 373- | Landline | Hollywood | 02/04/1994 | |
| (301) 374- | Landline | Waldorf | 02/11/1995 | |
| (301) 375- | Landline | Bryans Road | 02/04/1994 | |
| (301) 376- | Wireless | Laurel | 04/01/1997 | |
| (301) 377- | Landline | Laurel | Comcast Phone Of Northern Maryland | 10/11/1997 |
| (301) 378- | Landline | Frederick | Comcast Phone Of Northern Maryland | 02/20/2007 |
| (301) 379- | Wireless | Beltsville | Sprint | 01/25/1998 |
| (301) 380- | Landline | Rockville | 02/04/1994 | |
| (301) 382- | Wireless | Rockville | 10/15/1996 | |
| (301) 383- | Landline | Glenn Dale | Comcast Phone Of Northern Maryland | 10/11/1997 |
| (301) 384- | Landline | Silver Spring | 02/04/1994 | |
| (301) 385- | Wireless | Bethesda | Cingular Wireless | 04/01/1997 |
| (301) 386- | Landline | Hyattsville | 02/04/1994 | |
| (301) 387- | Landline | Swanton | 02/04/1994 | |
| (301) 388- | Landline | Silver Spring | 10/11/1997 | |
| (301) 389- | Landline | Laurel | Tw Telecom | 01/25/1998 |
| (301) 390- | Landline | Bowie | 02/04/1994 | |
| (301) 391- | Landline | Damascus | 02/11/1995 | |
| (301) 392- | Landline | La Plata | 07/06/1997 | |
| (301) 393- | Landline | Hagerstown | 01/25/1998 | |
| (301) 394- | Landline | Beltsville | 02/04/1994 | |
| (301) 395- | Wireless | Laurel | Verizon Wireless | 08/17/2004 |
| (301) 396- | Landline | Waldorf | 01/25/1998 | |
| (301) 397- | Wireless | Greenbelt | 02/11/1995 | |
| (301) 398- | Landline | Rockville | 10/09/2003 | |
| (301) 399- | Wireless | Waldorf | Sprint | 01/25/1998 |
| (301) 400- | Landline | Rockville | 03/29/2010 | |
| (301) 401- | Wireless | Frederick | Cingular Wireless | 02/04/1994 |
| (301) 402- | Landline | Bethesda | 02/04/1994 | |
| (301) 403- | Landline | Hyattsville | 02/04/1994 | |
| (301) 404- | Wireless | Beltsville | Sprint | 04/15/1996 |
| (301) 405- | Landline | Hyattsville | Paetec Comms | 02/04/1994 |
| (301) 406- | Wireless | Chevy Chase | USA Mobility Wireless | 02/04/1994 |
| (301) 407- | Landline | Poolesville | 07/01/1996 | |
| (301) 408- | Landline | Hyattsville | 07/01/1996 | |
| (301) 409- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 412- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 413- | Landline | Rockville | 02/04/1994 | |
| (301) 414- | Landline | Damascus | 02/04/1994 | |
| (301) 415- | Landline | Silver Spring | 02/04/1994 | |
| (301) 416- | Landline | Williamsport | 02/04/1994 | |
| (301) 417- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 418- | Landline | Frederick | 11/20/2002 | |
| (301) 419- | Landline | Beltsville | 02/04/1994 | |
| (301) 420- | Landline | Suitland | 02/04/1994 | |
| (301) 421- | Landline | Silver Spring | 02/04/1994 | |
| (301) 422- | Landline | Hyattsville | 02/04/1994 | |
| (301) 423- | Landline | Temple Hills | 02/04/1994 | |
| (301) 424- | Landline | Rockville | 02/04/1994 | |
| (301) 425- | Wireless | Beltsville | 09/11/1994 | |
| (301) 426- | Wireless | Beltsville | 04/15/1996 | |
| (301) 427- | Landline | Silver Spring | 02/04/1994 | |
| (301) 428- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 429- | Landline | Lanham | 01/11/1997 | |
| (301) 430- | Landline | Bowie | 10/11/1997 | |
| (301) 431- | Landline | Hyattsville | 02/04/1994 | |
| (301) 432- | Landline | Keedysville | 02/04/1994 | |
| (301) 433- | Landline | Fort Washington | 01/11/1997 | |
| (301) 434- | Landline | Hyattsville | 02/04/1994 | |
| (301) 435- | Landline | Bethesda | 07/04/1995 | |
| (301) 436- | Landline | Hyattsville | 02/04/1994 | |
| (301) 437- | Wireless | Beltsville | Sprint | 08/14/1998 |
| (301) 438- | Landline | Rockville | 02/04/1994 | |
| (301) 439- | Landline | Hyattsville | 02/04/1994 | |
| (301) 440- | Wireless | Capitol Heights | Sprint | 05/18/1998 |
| (301) 441- | Landline | Greenbelt | 02/04/1994 | |
| (301) 442- | Wireless | Beltsville | Sprint | 01/25/1998 |
| (301) 443- | Landline | Rockville | 02/04/1994 | |
| (301) 444- | Landline | Gaithersburg | 01/25/1998 | |
| (301) 445- | Landline | Hyattsville | 02/04/1994 | |
| (301) 446- | Landline | Greenbelt | 08/14/1998 | |
| (301) 447- | Landline | Emmitsburg | 02/04/1994 | |
| (301) 448- | Landline | Silver Spring | Comcast Phone Of Northern Maryland | 08/20/2000 |
| (301) 449- | Landline | Fort Washington | 02/04/1994 | |
| (301) 451- | Landline | Bethesda | 05/10/1999 | |
| (301) 452- | Wireless | Silver Spring | Verizon Wireless | 02/11/1995 |
| (301) 453- | Landline | Kitzmiller | 02/04/1994 | |
| (301) 454- | Landline | Hyattsville | 02/04/1994 | |
| (301) 455- | Wireless | Beltsville | Sprint | 01/25/1998 |
| (301) 456- | Landline | Mount Rainier | Comcast Phone Of Northern Maryland | 04/01/1997 |
| (301) 457- | Landline | Silver Spring | 02/11/1995 | |
| (301) 458- | Landline | Mount Rainier | Teleport Comms America | 07/04/1995 |
| (301) 459- | Landline | Lanham | 02/04/1994 | |
| (301) 460- | Landline | Rockville | 02/04/1994 | |
| (301) 461- | Wireless | Rockville | Verizon Wireless | 05/18/1998 |
| (301) 462- | Wireless | Myersville | Sprint | 10/11/1997 |
| (301) 463- | Landline | Lonaconing | 02/04/1994 | |
| (301) 464- | Landline | Bowie | 02/04/1994 | |
| (301) 465- | Wireless | Myersville | Sprint | 01/11/1997 |
| (301) 466- | Wireless | Silver Spring | Verizon Wireless | 07/04/1995 |
| (301) 467- | Wireless | Silver Spring | Verizon Wireless | 01/10/1996 |
| (301) 468- | Landline | Rockville | 02/04/1994 | |
| (301) 469- | Landline | Bethesda | 02/04/1994 | |
| (301) 470- | Landline | Laurel | 02/04/1994 | |
| (301) 471- | Wireless | Frederick | Verizon Wireless | 04/15/1996 |
| (301) 472- | Landline | Mechanicsville | 09/11/1994 | |
| (301) 473- | Landline | Frederick | 02/04/1994 | |
| (301) 474- | Landline | Greenbelt | 02/04/1994 | |
| (301) 475- | Landline | Leonardtown | 02/04/1994 | |
| (301) 476- | Landline | Silver Spring | 09/11/1994 | |
| (301) 477- | Landline | College Park | Comcast Phone Of Northern Maryland | 10/11/1997 |
| (301) 478- | Landline | Oldtown | 02/04/1994 | |
| (301) 479- | Landline | College Park | Mci Worldcom Comms | 07/04/1995 |
| (301) 480- | Landline | Bethesda | 02/04/1994 | |
| (301) 481- | Wireless | Leonardtown | Verizon Wireless | 04/15/1996 |
| (301) 482- | Landline | Damascus | 04/15/1996 | |
| (301) 483- | Landline | Laurel | 04/15/1996 | |
| (301) 484- | Landline | Oxon Hill | Comcast Phone Of Northern Maryland | 04/01/1997 |
| (301) 485- | Landline | Oxon Hill | Comcast Phone Of Northern Maryland | 04/01/1997 |
| (301) 486- | Landline | Greenbelt | 01/11/1997 | |
| (301) 487- | Landline | Myersville | 02/04/1994 | |
| (301) 488- | Wireless | Greenbelt | 01/25/1998 | |
| (301) 489- | Landline | Greenbelt | 09/11/1994 | |
| (301) 490- | Landline | Laurel | 02/04/1994 | |
| (301) 491- | Wireless | Hagerstown | Uscoc Of Cumberland DBA United States Cel Md | 02/04/1994 |
| (301) 492- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 493- | Landline | Rockville | 02/04/1994 | |
| (301) 494- | Landline | Upper Marlboro | 10/15/1996 | |
| (301) 495- | Landline | Silver Spring | 02/04/1994 | |
| (301) 496- | Landline | Bethesda | 02/04/1994 | |
| (301) 497- | Landline | Laurel | 02/04/1994 | |
| (301) 498- | Landline | Laurel | 02/04/1994 | |
| (301) 499- | Landline | Capitol Heights | 02/04/1994 | |
| (301) 500- | Landline | Chevy Chase | Xo Maryland | 09/01/2010 |
| (301) 501- | Wireless | Oakland | Cingular Wireless | 02/04/1994 |
| (301) 502- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 503- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 504- | Landline | Silver Spring | 02/04/1994 | |
| (301) 505- | Landline | Temple Hills | 02/04/1994 | |
| (301) 506- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 507- | Landline | Greenbelt | 02/04/1994 | |
| (301) 508- | Wireless | Myersville | Cingular Wireless | 05/18/1998 |
| (301) 509- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 510- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 512- | Wireless | Silver Spring | Verizon Wireless | 01/10/1996 |
| (301) 513- | Landline | Greenbelt | 02/04/1994 | |
| (301) 514- | Wireless | Frederick | Verizon Wireless | 07/01/1996 |
| (301) 515- | Landline | Gaithersburg | 01/10/1996 | |
| (301) 516- | Landline | Suitland | 04/01/1997 | |
| (301) 517- | Landline | Rockville | 02/04/1994 | |
| (301) 518- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 519- | Landline | Gaithersburg | 04/01/1997 | |
| (301) 520- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 521- | Landline | Oxon Hill | 04/01/1997 | |
| (301) 522- | Wireless | Rockville | 04/01/1997 | |
| (301) 523- | Wireless | Beltsville | Sprint | 10/15/1996 |
| (301) 524- | Wireless | Frederick | Sprint | 08/14/1998 |
| (301) 525- | Landline | Gaithersburg | Quantum Telecom | 10/16/2003 |
| (301) 526- | Wireless | Silver Spring | Cingular Wireless | 08/14/1998 |
| (301) 527- | Landline | Gaithersburg | 02/11/1995 | |
| (301) 528- | Landline | Gaithersburg | 08/14/1998 | |
| (301) 529- | Wireless | Rockville | Cingular Wireless | 08/14/1998 |
| (301) 530- | Landline | Rockville | 02/04/1994 | |
| (301) 531- | Landline | Hyattsville | Starpower Comms | 11/20/1998 |
| (301) 533- | Landline | Oakland | 08/14/1998 | |
| (301) 534- | Landline | Indian Head | Ymax Comms Corp. | 11/15/2006 |
| (301) 535- | Wireless | Waldorf | Cingular Wireless | 08/14/1998 |
| (301) 536- | Wireless | Leonardtown | Sprint | 11/20/1998 |
| (301) 537- | Wireless | Beltsville | Sprint | 08/14/1998 |
| (301) 538- | Wireless | Bethesda | Cingular Wireless | 02/11/1995 |
| (301) 539- | Landline | La Plata | Teleport Comms America | 08/14/1998 |
| (301) 540- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 541- | Landline | Mount Rainier | Teleport Comms America | 11/20/1998 |
| (301) 542- | Landline | Waldorf | Teleport Comms America | 08/14/1998 |
| (301) 543- | Landline | Laurel | Teleport Comms America | 10/11/1997 |
| (301) 544- | Wireless | Rockville | 11/20/1998 | |
| (301) 545- | Landline | Rockville | 10/11/1997 | |
| (301) 546- | Landline | Landover | 04/07/2014 | |
| (301) 547- | Landline | Mount Rainier | Teleport Comms America | 01/10/1996 |
| (301) 548- | Landline | Gaithersburg | 02/11/1995 | |
| (301) 549- | Landline | Laurel | 09/11/1994 | |
| (301) 551- | Landline | Kensington | Baltimore-washington Telephone (bwt) | 06/13/2000 |
| (301) 552- | Landline | Lanham | 02/04/1994 | |
| (301) 553- | Wireless | Waldorf | USA Mobility Wireless | 05/18/1998 |
| (301) 554- | Wireless | Bethesda | USA Mobility Wireless | 05/18/1998 |
| (301) 556- | Landline | Gaithersburg | Teleport Comms America | 10/11/1997 |
| (301) 557- | Landline | Mount Rainier | Broadwing Comms. | 09/06/2011 |
| (301) 558- | Wireless | College Park | USA Mobility Wireless | 05/18/1998 |
| (301) 559- | Landline | Hyattsville | 02/04/1994 | |
| (301) 560- | Landline | Hyattsville | Paetec Comms | 08/14/1998 |
| (301) 561- | Landline | Silver Spring | Baltimore-washington Telephone (bwt) | 03/03/2001 |
| (301) 562- | Landline | Silver Spring | 04/01/1997 | |
| (301) 563- | Landline | Silver Spring | 04/01/1997 | |
| (301) 564- | Landline | Rockville | 02/04/1994 | |
| (301) 565- | Landline | Silver Spring | 02/04/1994 | |
| (301) 566- | Wireless | Beltsville | 10/11/1997 | |
| (301) 567- | Landline | Oxon Hill | 02/04/1994 | |
| (301) 568- | Landline | Suitland | 02/04/1994 | |
| (301) 569- | Wireless | Gaithersburg | Verizon Wireless | 08/14/1998 |
| (301) 570- | Landline | Ashton | 02/04/1994 | |
| (301) 571- | Landline | Rockville | 02/04/1994 | |
| (301) 572- | Landline | Beltsville | 02/04/1994 | |
| (301) 573- | Wireless | Hagerstown | Sprint | 11/20/1998 |
| (301) 574- | Landline | Upper Marlboro | 02/11/1995 | |
| (301) 575- | Landline | Laurel | Us Lec | 08/14/1998 |
| (301) 576- | Landline | Silver Spring | Paetec Comms | 08/14/1998 |
| (301) 577- | Landline | Lanham | 02/04/1994 | |
| (301) 578- | Landline | Silver Spring | 10/15/1996 | |
| (301) 579- | Landline | Brandywine | 02/04/1994 | |
| (301) 580- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 581- | Landline | Rockville | 04/01/1997 | |
| (301) 582- | Landline | Hagerstown | 02/04/1994 | |
| (301) 583- | Landline | Hyattsville | 01/25/1998 | |
| (301) 584- | Landline | Silver Spring | Baltimore-washington Telephone (bwt) | 06/13/2000 |
| (301) 585- | Landline | Silver Spring | 02/04/1994 | |
| (301) 586- | Landline | Beltsville | 01/10/1996 | |
| (301) 587- | Landline | Silver Spring | 02/04/1994 | |
| (301) 588- | Landline | Silver Spring | 02/04/1994 | |
| (301) 589- | Landline | Silver Spring | 02/04/1994 | |
| (301) 590- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 591- | Landline | Gaithersburg | Paetec Comms | 08/14/1998 |
| (301) 592- | Landline | Silver Spring | 10/11/1997 | |
| (301) 593- | Landline | Silver Spring | 02/04/1994 | |
| (301) 594- | Landline | Bethesda | 02/04/1994 | |
| (301) 595- | Landline | Beltsville | 02/04/1994 | |
| (301) 596- | Landline | Columbia | 02/04/1994 | |
| (301) 597- | Landline | Hancock | New Frontiers Telecom | 06/13/2000 |
| (301) 598- | Landline | Rockville | 02/04/1994 | |
| (301) 599- | Landline | Clinton | 02/04/1994 | |
| (301) 600- | Landline | Frederick | 07/06/2006 | |
| (301) 601- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 602- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 603- | Landline | Rockville | 07/01/1996 | |
| (301) 604- | Landline | Laurel | 02/04/1994 | |
| (301) 605- | Landline | Rockville | 10/15/1996 | |
| (301) 606- | Wireless | Frederick | Verizon Wireless | 02/04/1994 |
| (301) 607- | Landline | New Market | 02/04/1994 | |
| (301) 608- | Landline | Silver Spring | 02/04/1994 | |
| (301) 609- | Landline | La Plata | 02/04/1994 | |
| (301) 610- | Landline | Rockville | 10/15/1996 | |
| (301) 612- | Wireless | Sandy Spring | Teleport Comms America | 10/11/2012 |
| (301) 613- | Wireless | Beltsville | Sprint | 07/01/1996 |
| (301) 614- | Landline | Greenbelt | 01/10/1996 | |
| (301) 615- | Wireless | Greenbelt | 02/04/1994 | |
| (301) 616- | Wireless | Oakland | Uscoc Of Cumberland DBA United States Cel Md | 02/04/1994 |
| (301) 617- | Landline | Laurel | 02/11/1995 | |
| (301) 618- | Landline | Hyattsville | 02/04/1994 | |
| (301) 619- | Landline | Frederick | 02/04/1994 | |
| (301) 620- | Landline | Frederick | 02/04/1994 | |
| (301) 621- | Landline | Glenn Dale | 02/04/1994 | |
| (301) 622- | Landline | Silver Spring | 02/04/1994 | |
| (301) 623- | Landline | Mount Rainier | Teleport Comms America | 10/11/1997 |
| (301) 624- | Landline | Frederick | 01/10/1996 | |
| (301) 625- | Landline | Silver Spring | 01/10/1996 | |
| (301) 626- | Wireless | Silver Spring | 05/18/1998 | |
| (301) 627- | Landline | Upper Marlboro | 02/04/1994 | |
| (301) 628- | Landline | Mount Rainier | Teleport Comms America | 01/10/1996 |
| (301) 629- | Wireless | Glenn Dale | 02/04/1994 | |
| (301) 630- | Landline | Temple Hills | 02/04/1994 | |
| (301) 631- | Landline | Frederick | 02/11/1995 | |
| (301) 632- | Landline | Waldorf | 01/10/1996 | |
| (301) 633- | Wireless | Bethesda | Cingular Wireless | 02/11/1995 |
| (301) 634- | Landline | Mount Rainier | Teleport Comms America | 10/11/1997 |
| (301) 635- | Landline | Myersville | New Frontiers Telecom | 06/13/2000 |
| (301) 636- | Landline | Hyattsville | 06/13/2000 | |
| (301) 637- | Landline | Rockville | Level 3 Comms | 08/14/1998 |
| (301) 638- | Landline | Waldorf | 01/10/1996 | |
| (301) 639- | Wireless | Frederick | Verizon Wireless | 02/11/1995 |
| (301) 640- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 641- | Wireless | Silver Spring | Verizon Wireless | 09/11/1994 |
| (301) 642- | Wireless | Bethesda | Cingular Wireless | 01/25/1998 |
| (301) 643- | Wireless | Waldorf | Verizon Wireless | 09/11/1994 |
| (301) 644- | Landline | Frederick | 08/14/1998 | |
| (301) 645- | Landline | Waldorf | 02/04/1994 | |
| (301) 646- | Wireless | Bethesda | Cingular Wireless | 01/10/1996 |
| (301) 647- | Wireless | Laurel | 01/10/1996 | |
| (301) 648- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 649- | Landline | Silver Spring | 02/04/1994 | |
| (301) 650- | Landline | Silver Spring | 02/04/1994 | |
| (301) 651- | Wireless | Silver Spring | Verizon Wireless | 02/11/1995 |
| (301) 652- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 653- | Wireless | Waldorf | Cingular Wireless | 01/10/1996 |
| (301) 654- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 655- | Wireless | Bethesda | Cingular Wireless | 04/15/1996 |
| (301) 656- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 657- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 658- | Landline | Sandy Spring | Teleport Comms America | 10/11/1997 |
| (301) 659- | Wireless | Waldorf | Cingular Wireless | 05/18/1998 |
| (301) 660- | Wireless | Keedysville | Cingular Wireless | 03/19/2004 |
| (301) 661- | Wireless | Bethesda | Cingular Wireless | 09/11/1994 |
| (301) 662- | Landline | Frederick | 02/04/1994 | |
| (301) 663- | Landline | Frederick | 02/04/1994 | |
| (301) 664- | Landline | Chevy Chase | 01/10/1996 | |
| (301) 665- | Landline | Hagerstown | 01/10/1996 | |
| (301) 666- | Landline | Glenn Dale | Teleport Comms America | 08/14/1998 |
| (301) 667- | Wireless | Myersville | Cingular Wireless | 09/11/1994 |
| (301) 668- | Landline | Frederick | 08/14/1998 | |
| (301) 669- | Landline | Suitland | 09/11/1994 | |
| (301) 670- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 671- | Landline | Hagerstown | New Frontiers Telecom | 06/13/2000 |
| (301) 672- | Wireless | Tall Timbers | Sprint | 11/20/1998 |
| (301) 673- | Landline | Frederick | New Frontiers Telecom | 06/13/2000 |
| (301) 674- | Wireless | Bethesda | Sprint | 11/20/1998 |
| (301) 675- | Wireless | Silver Spring | Omnipoint Comms Cap Operations | 06/13/2000 |
| (301) 676- | Wireless | Frederick | Cingular Wireless | 07/06/1997 |
| (301) 677- | Landline | Glenn Dale | Teleport Comms America | 02/04/1994 |
| (301) 678- | Landline | Hancock | 02/04/1994 | |
| (301) 679- | Landline | Mount Rainier | Teleport Comms America | 08/14/1998 |
| (301) 680- | Landline | Silver Spring | 02/04/1994 | |
| (301) 681- | Landline | Silver Spring | 02/04/1994 | |
| (301) 682- | Landline | Frederick | 02/11/1995 | |
| (301) 683- | Landline | Mount Rainier | Teleport Comms America | 08/14/1998 |
| (301) 684- | Landline | Indian Head | Teleport Comms America | 08/14/1998 |
| (301) 685- | Landline | Damascus | Teleport Comms America | 08/14/1998 |
| (301) 686- | Landline | Oxon Hill | 05/10/1999 | |
| (301) 687- | Landline | Frostburg | 07/04/1995 | |
| (301) 688- | Landline | Laurel | 02/04/1994 | |
| (301) 689- | Landline | Frostburg | 02/04/1994 | |
| (301) 690- | Landline | Leonardtown | Idt America Corp | 05/23/2007 |
| (301) 691- | Landline | Poolesville | Teleport Comms America | 08/14/1998 |
| (301) 692- | Landline | Mount Rainier | Teleport Comms America | 08/14/1998 |
| (301) 693- | Wireless | Frederick | Omnipoint Comms Cap Operations | 06/13/2000 |
| (301) 694- | Landline | Frederick | 02/04/1994 | |
| (301) 695- | Landline | Frederick | 02/04/1994 | |
| (301) 696- | Landline | Frederick | 02/04/1994 | |
| (301) 697- | Wireless | Cumberland | Cingular Wireless | 02/04/1994 |
| (301) 698- | Landline | Frederick | 02/04/1994 | |
| (301) 699- | Landline | Hyattsville | 02/04/1994 | |
| (301) 701- | Wireless | Hyattsville | 02/04/1994 | |
| (301) 702- | Landline | Temple Hills | 02/04/1994 | |
| (301) 703- | Landline | Mount Airy | Level 3 Comms | 08/29/2002 |
| (301) 704- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 705- | Landline | Waldorf | 02/04/1994 | |
| (301) 706- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 707- | Wireless | Cumberland | Uscoc Of Cumberland DBA United States Cel Md | 02/04/1994 |
| (301) 708- | Wireless | Greenbelt | Cavalier Telephone Mid-atlantic | 09/20/2011 |
| (301) 709- | Wireless | Greenbelt | USA Mobility Wireless | 02/04/1994 |
| (301) 710- | Landline | Waldorf | Level 3 Comms | 12/30/2005 |
| (301) 712- | Landline | Frederick | Mci Worldcom Comms | 03/27/2005 |
| (301) 713- | Landline | Silver Spring | 02/04/1994 | |
| (301) 714- | Landline | Hagerstown | 02/04/1994 | |
| (301) 715- | Landline | Upper Marlboro | Teleport Comms America | 08/14/1998 |
| (301) 716- | Wireless | Beltsville | 07/01/1996 | |
| (301) 717- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 718- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 719- | Landline | Mount Rainier | Teleport Comms America | 08/14/1998 |
| (301) 720- | Landline | Brandywine | Teleport Comms America | 08/14/1998 |
| (301) 721- | Landline | Gaithersburg | 10/15/1996 | |
| (301) 722- | Landline | Cumberland | 02/04/1994 | |
| (301) 723- | Landline | Cumberland | 05/18/1998 | |
| (301) 724- | Landline | Cumberland | 02/04/1994 | |
| (301) 725- | Landline | Laurel | 02/04/1994 | |
| (301) 727- | Landline | Capitol Heights | Baltimore-washington Telephone (bwt) | 06/13/2000 |
| (301) 728- | Wireless | Silver Spring | Omnipoint Comms Cap Operations | 06/13/2000 |
| (301) 729- | Landline | Cumberland | 02/04/1994 | |
| (301) 730- | Wireless | Myersville | Cingular Wireless | 11/20/1998 |
| (301) 731- | Landline | Lanham | 02/04/1994 | |
| (301) 732- | Wireless | Greenbelt | Metro PCS | 10/04/2011 |
| (301) 733- | Landline | Hagerstown | 02/04/1994 | |
| (301) 734- | Landline | Silver Spring | 02/11/1995 | |
| (301) 735- | Landline | Suitland | 02/04/1994 | |
| (301) 736- | Landline | Suitland | 02/04/1994 | |
| (301) 737- | Landline | Lexington Park | 02/04/1994 | |
| (301) 738- | Landline | Rockville | 02/04/1994 | |
| (301) 739- | Landline | Hagerstown | 02/04/1994 | |
| (301) 740- | Landline | Gaithersburg | 04/22/2004 | |
| (301) 741- | Landline | Laurel | Level 3 Comms | 08/14/1998 |
| (301) 742- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 743- | Landline | Indian Head | 02/04/1994 | |
| (301) 744- | Landline | Indian Head | 10/11/1997 | |
| (301) 745- | Landline | Hagerstown | 02/04/1994 | |
| (301) 746- | Landline | Accident | 02/04/1994 | |
| (301) 747- | Landline | Mount Rainier | Teleport Comms America | 11/20/1998 |
| (301) 748- | Wireless | Frederick | Sprint | 04/01/1997 |
| (301) 749- | Landline | Oxon Hill | 09/11/1994 | |
| (301) 750- | Landline | Friendsville | Core Comms | 03/18/2004 |
| (301) 751- | Wireless | Waldorf | Verizon Wireless | 01/10/1996 |
| (301) 752- | Wireless | Waldorf | Verizon Wireless | 08/14/1998 |
| (301) 753- | Landline | Oxon Hill | 02/04/1994 | |
| (301) 754- | Landline | Silver Spring | 09/11/1994 | |
| (301) 755- | Landline | Silver Spring | Mci Worldcom Comms | 07/04/1995 |
| (301) 756- | Landline | Laurel | Tw Telecom | 01/25/1998 |
| (301) 757- | Landline | Patuxent River | 01/11/1997 | |
| (301) 758- | Wireless | Silver Spring | Verizon Wireless | 09/11/1994 |
| (301) 759- | Landline | Cumberland | 02/04/1994 | |
| (301) 760- | Landline | Bethesda | Level 3 Comms | 02/27/2002 |
| (301) 761- | Landline | Kensington | Level 3 Comms | 02/27/2002 |
| (301) 762- | Landline | Rockville | 02/04/1994 | |
| (301) 763- | Landline | Suitland | 02/04/1994 | |
| (301) 764- | Landline | Waldorf | 01/10/1996 | |
| (301) 765- | Landline | Bethesda | 10/15/1996 | |
| (301) 766- | Landline | Hagerstown | 04/15/1996 | |
| (301) 767- | Landline | Bethesda | 10/15/1996 | |
| (301) 768- | Landline | Cabin John | Level 3 Comms | 02/27/2002 |
| (301) 769- | Landline | Avenue | 02/04/1994 | |
| (301) 770- | Landline | Rockville | 02/04/1994 | |
| (301) 771- | Wireless | Chevy Chase | 04/01/1997 | |
| (301) 772- | Landline | Hyattsville | 02/04/1994 | |
| (301) 773- | Landline | Hyattsville | 02/04/1994 | |
| (301) 774- | Landline | Ashton | 02/04/1994 | |
| (301) 775- | Wireless | Silver Spring | Verizon Wireless | 01/10/1996 |
| (301) 776- | Landline | Laurel | 02/04/1994 | |
| (301) 777- | Landline | Cumberland | 02/04/1994 | |
| (301) 778- | Landline | Capitol Heights | Mci Worldcom Comms | 07/04/1995 |
| (301) 779- | Landline | Hyattsville | 02/04/1994 | |
| (301) 780- | Landline | Upper Marlboro | 01/25/1998 | |
| (301) 781- | Landline | Frostburg | New Frontiers Telecom | 06/13/2000 |
| (301) 782- | Landline | Brandywine | 02/04/1994 | |
| (301) 783- | Landline | Cumberland | New Frontiers Telecom | 06/13/2000 |
| (301) 784- | Landline | Cumberland | 09/11/1994 | |
| (301) 785- | Wireless | Silver Spring | Verizon Wireless | 08/14/1998 |
| (301) 786- | Landline | Mccoole | 01/10/1996 | |
| (301) 787- | Wireless | Silver Spring | Verizon Wireless | 08/14/1998 |
| (301) 788- | Wireless | Frederick | Verizon Wireless | 08/14/1998 |
| (301) 789- | Landline | Hyattsville | Core Comms | 08/13/2002 |
| (301) 790- | Landline | Hagerstown | 02/04/1994 | |
| (301) 791- | Landline | Hagerstown | 02/04/1994 | |
| (301) 792- | Wireless | Silver Spring | Omnipoint Comms Cap Operations | 06/13/2000 |
| (301) 793- | Wireless | Silver Spring | Omnipoint Comms Cap Operations | 06/13/2000 |
| (301) 794- | Landline | Lanham | 02/04/1994 | |
| (301) 795- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 796- | Landline | College Park | 06/30/2003 | |
| (301) 797- | Landline | Hagerstown | 02/04/1994 | |
| (301) 798- | Landline | New Market | 07/01/1996 | |
| (301) 799- | Landline | Keedysville | Core Comms | 03/18/2004 |
| (301) 800- | Wireless | Hagerstown | Virginia PCS Alliance, L.c. | 04/29/2010 |
| (301) 801- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 802- | Wireless | Silver Spring | Verizon Wireless | 10/15/1996 |
| (301) 803- | Landline | Rockville | 02/04/1994 | |
| (301) 804- | Landline | Sandy Spring | MCI Metro ATS | 11/20/1998 |
| (301) 805- | Landline | Bowie | 02/04/1994 | |
| (301) 806- | Wireless | Beltsville | Sprint | 07/01/1996 |
| (301) 807- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 808- | Landline | Capitol Heights | 02/04/1994 | |
| (301) 809- | Landline | Bowie | 02/04/1994 | |
| (301) 810- | Landline | Monrovia | AT&T; Local | 08/14/1998 |
| (301) 812- | Landline | North Beach | 07/01/1996 | |
| (301) 813- | Landline | Bethesda | Baltimore-washington Telephone (bwt) | 06/30/2001 |
| (301) 814- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 815- | Landline | Frederick | 02/04/1994 | |
| (301) 816- | Landline | Rockville | 02/04/1994 | |
| (301) 817- | Landline | Suitland | 02/04/1994 | |
| (301) 818- | Landline | Waldorf | 02/04/1994 | |
| (301) 819- | Wireless | Silver Spring | 07/01/1996 | |
| (301) 820- | Landline | Gaithersburg | AT&T; Local | 11/20/1998 |
| (301) 821- | Landline | Laurel | AT&T; Local | 08/14/1998 |
| (301) 822- | Landline | Mount Rainier | AT&T; Local | 08/14/1998 |
| (301) 823- | Landline | Mount Rainier | AT&T; Local | 08/14/1998 |
| (301) 824- | Landline | Smithsburg | 02/04/1994 | |
| (301) 825- | Landline | Rockville | AT&T; Local | 08/14/1998 |
| (301) 826- | Landline | Lexington Park | 02/04/1994 | |
| (301) 827- | Landline | Bethesda | 02/04/1994 | |
| (301) 828- | Landline | Bethesda | AT&T; Local | 08/14/1998 |
| (301) 829- | Landline | Mount Airy | 02/04/1994 | |
| (301) 830- | Landline | Silver Spring | AT&T; Local | 08/14/1998 |
| (301) 831- | Landline | Adamstown | 02/04/1994 | |
| (301) 832- | Landline | Mount Rainier | AT&T; Local | 08/14/1998 |
| (301) 833- | Landline | Glenn Dale | Teleport Comms America | 11/11/2003 |
| (301) 834- | Landline | Brunswick | 02/04/1994 | |
| (301) 836- | Landline | Temple Hills | 07/04/1995 | |
| (301) 837- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 838- | Landline | Rockville | 07/04/1995 | |
| (301) 839- | Landline | Oxon Hill | 02/04/1994 | |
| (301) 840- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 841- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 842- | Landline | Clear Spring | 02/04/1994 | |
| (301) 843- | Landline | Waldorf | 02/04/1994 | |
| (301) 844- | Wireless | Mount Rainier | Sprint | 10/04/2011 |
| (301) 845- | Landline | Walkersville | 02/04/1994 | |
| (301) 846- | Landline | Frederick | 02/04/1994 | |
| (301) 847- | Landline | Beltsville | 02/04/1994 | |
| (301) 848- | Wireless | Waldorf | Verizon Wireless | 08/14/1998 |
| (301) 849- | Landline | Oakland | New Frontiers Telecom | 06/13/2000 |
| (301) 850- | Landline | Glenn Dale | Level 3 Comms | 08/04/2002 |
| (301) 851- | Landline | Hyattsville | 02/04/1994 | |
| (301) 852- | Landline | Hyattsville | 02/04/1994 | |
| (301) 853- | Landline | Hyattsville | 02/04/1994 | |
| (301) 854- | Landline | Columbia | 02/04/1994 | |
| (301) 855- | Landline | Upper Marlboro | 02/04/1994 | |
| (301) 856- | Landline | Clinton | 02/04/1994 | |
| (301) 857- | Landline | Clear Spring | Core Comms | 07/12/2002 |
| (301) 858- | Landline | Glenn Dale | 02/04/1994 | |
| (301) 859- | Landline | Oxon Hill | Level 3 Comms | 01/09/2002 |
| (301) 860- | Landline | Bowie | 08/20/2000 | |
| (301) 861- | Landline | Waldorf | Level 3 Comms | 08/14/1998 |
| (301) 862- | Landline | Lexington Park | 02/04/1994 | |
| (301) 863- | Landline | Lexington Park | 02/04/1994 | |
| (301) 864- | Landline | Hyattsville | 02/04/1994 | |
| (301) 865- | Landline | New Market | 02/04/1994 | |
| (301) 866- | Landline | Lexington Park | 10/15/1996 | |
| (301) 867- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 868- | Landline | Clinton | 02/04/1994 | |
| (301) 869- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 870- | Landline | Waldorf | 02/04/1994 | |
| (301) 871- | Landline | Rockville | 02/04/1994 | |
| (301) 872- | Landline | Ridge | 02/04/1994 | |
| (301) 873- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 874- | Landline | Adamstown | 02/04/1994 | |
| (301) 875- | Landline | Laurel | Verizon Wireless | 03/27/2005 |
| (301) 876- | Landline | Cumberland | Level 3 Comms | 05/02/2002 |
| (301) 877- | Landline | Clinton | 01/11/1997 | |
| (301) 878- | Landline | Baltimore | 01/10/1996 | |
| (301) 879- | Landline | Silver Spring | 02/11/1995 | |
| (301) 880- | Landline | Tall Timbers | Level 3 Comms | 08/14/1998 |
| (301) 881- | Landline | Rockville | 02/04/1994 | |
| (301) 882- | Landline | New Market | Core Comms | 03/18/2004 |
| (301) 883- | Landline | Hyattsville | 09/11/1994 | |
| (301) 884- | Landline | Mechanicsville | 02/04/1994 | |
| (301) 885- | Landline | Waldorf | 02/11/1995 | |
| (301) 886- | Landline | Laurel | 07/04/1995 | |
| (301) 887- | Landline | Hyattsville | 02/11/1995 | |
| (301) 888- | Landline | Brandywine | 02/04/1994 | |
| (301) 889- | Landline | Glenn Dale | 01/10/1996 | |
| (301) 890- | Landline | Beltsville | 02/04/1994 | |
| (301) 891- | Landline | Hyattsville | 02/04/1994 | |
| (301) 892- | Landline | Hyattsville | 03/11/2005 | |
| (301) 893- | Landline | Waldorf | 01/10/1996 | |
| (301) 894- | Landline | Temple Hills | 02/04/1994 | |
| (301) 895- | Landline | Grantsville | 02/04/1994 | |
| (301) 896- | Landline | Rockville | 01/10/1996 | |
| (301) 897- | Landline | Rockville | 02/04/1994 | |
| (301) 898- | Landline | Walkersville | 02/04/1994 | |
| (301) 899- | Landline | Temple Hills | 02/04/1994 | |
| (301) 900- | Landline | Frederick | 10/22/2013 | |
| (301) 901- | Landline | Greenbelt | 02/04/1994 | |
| (301) 902- | Landline | Beltsville | 02/04/1994 | |
| (301) 903- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 904- | Wireless | Leonardtown | Verizon Wireless | 02/04/1994 |
| (301) 905- | Landline | Silver Spring | 02/04/1994 | |
| (301) 906- | Wireless | Bethesda | Cingular Wireless | 10/15/1996 |
| (301) 907- | Landline | Chevy Chase | 05/18/1998 | |
| (301) 908- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 909- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 910- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 912- | Landline | Odenton | 02/04/1994 | |
| (301) 913- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 914- | Landline | Mc Henry | Mountain Comms DBA Procom | 12/27/2012 |
| (301) 915- | Landline | Bethesda | Starpower Comms | 11/20/1998 |
| (301) 916- | Landline | Poolesville | 02/04/1994 | |
| (301) 917- | Landline | Rockville | Starpower Comms | 08/14/1998 |
| (301) 918- | Landline | Lanham | 02/04/1994 | |
| (301) 919- | Wireless | Bethesda | Cingular Wireless | 02/04/1994 |
| (301) 920- | Landline | Silver Spring | Starpower Comms | 08/14/1998 |
| (301) 921- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 922- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 923- | Wireless | Hyattsville | 09/11/1994 | |
| (301) 924- | Landline | Ashton | 02/04/1994 | |
| (301) 925- | Landline | Hyattsville | 02/04/1994 | |
| (301) 926- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 927- | Landline | Hyattsville | 02/04/1994 | |
| (301) 928- | Wireless | Silver Spring | Verizon Wireless | 02/11/1995 |
| (301) 929- | Landline | Kensington | 02/04/1994 | |
| (301) 930- | Wireless | Silver Spring | 02/04/1994 | |
| (301) 931- | Landline | Beltsville | 07/04/1995 | |
| (301) 932- | Landline | La Plata | 02/04/1994 | |
| (301) 933- | Landline | Kensington | 02/04/1994 | |
| (301) 934- | Landline | La Plata | 02/04/1994 | |
| (301) 935- | Landline | Hyattsville | 02/04/1994 | |
| (301) 937- | Landline | Beltsville | 02/04/1994 | |
| (301) 938- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 939- | Landline | Laurel | 04/15/1996 | |
| (301) 940- | Wireless | Silver Spring | 02/04/1994 | |
| (301) 941- | Landline | Chevy Chase | 02/11/1995 | |
| (301) 942- | Landline | Kensington | 02/04/1994 | |
| (301) 943- | Wireless | Silver Spring | Verizon Wireless | 04/15/1996 |
| (301) 944- | Landline | Gaithersburg | MCI Metro ATS | 11/20/1998 |
| (301) 945- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 946- | Landline | Kensington | 02/04/1994 | |
| (301) 947- | Landline | Gaithersburg | 04/15/1996 | |
| (301) 948- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 949- | Landline | Kensington | 02/04/1994 | |
| (301) 951- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 952- | Landline | Upper Marlboro | 02/04/1994 | |
| (301) 953- | Landline | Laurel | 02/04/1994 | |
| (301) 955- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 956- | Landline | Rockville | 05/22/2002 | |
| (301) 957- | Landline | Laurel | MCI Metro ATS | 11/20/1998 |
| (301) 960- | Landline | Silver Spring | MCI Metro ATS | 11/20/1998 |
| (301) 961- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 962- | Landline | Kensington | 01/11/1997 | |
| (301) 963- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 964- | Wireless | Myersville | Cingular Wireless | 04/15/1996 |
| (301) 965- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 966- | Landline | Hyattsville | MCI Metro ATS | 11/20/1998 |
| (301) 967- | Landline | Suitland | 02/04/1994 | |
| (301) 968- | Landline | Bethesda | Mci Worldcom Comms | 07/04/1995 |
| (301) 969- | Landline | Brunswick | Comcast Phone Of Northern Maryland | 03/06/2007 |
| (301) 970- | Landline | Annapolis | 02/04/1994 | |
| (301) 971- | Landline | Oxon Hill | Starpower Comms | 11/20/1998 |
| (301) 972- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 973- | Landline | Glenn Dale | 02/04/1994 | |
| (301) 974- | Landline | Laurel | Starpower Comms | 11/20/1998 |
| (301) 975- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 976- | Baltimore-washington Telephone (bwt) | 10/17/2005 | ||
| (301) 977- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 978- | Landline | Gaithersburg | 10/11/1997 | |
| (301) 979- | Landline | Gaithersburg | 04/15/1996 | |
| (301) 980- | Wireless | Silver Spring | Verizon Wireless | 02/04/1994 |
| (301) 981- | Landline | Mount Rainier | Tw Telecom | 02/04/1994 |
| (301) 982- | Landline | Greenbelt | 02/04/1994 | |
| (301) 983- | Landline | Bethesda | 02/04/1994 | |
| (301) 984- | Landline | Rockville | 02/04/1994 | |
| (301) 985- | Landline | Hyattsville | 02/04/1994 | |
| (301) 986- | Landline | Chevy Chase | 02/04/1994 | |
| (301) 987- | Landline | Gaithersburg | 10/11/1997 | |
| (301) 988- | Wireless | Hagerstown | Uscoc Of Cumberland DBA United States Cel Md | 07/06/1997 |
| (301) 989- | Landline | Silver Spring | 02/04/1994 | |
| (301) 990- | Landline | Gaithersburg | 02/04/1994 | |
| (301) 991- | Wireless | Hagerstown | Sprint | 04/15/1996 |
| (301) 992- | Wireless | Hagerstown | Sprint | 10/11/1997 |
| (301) 993- | Wireless | Greenbelt | 11/20/1998 | |
| (301) 994- | Landline | Valley Lee | 02/04/1994 | |
| (301) 995- | Landline | Patuxent River | 08/14/1998 | |
| (301) 996- | Wireless | Beltsville | Sprint | 01/10/1996 |
| (301) 997- | Landline | Leonardtown | 01/25/1998 | |
| (301) 998- | Landline | Rockville | 01/10/1996 |