| Comcast Maryland | COMMC | Montgomery County MD | Maryland | Montgomery |
| Comcast Maryland | COMPG | Prince Georges Co MD | Maryland | Prince George's |
| Comcast Maryland | COMSOMD | Southern Maryland | Maryland | Calvert, Charles, St. Mary's |
| MetroCast Communications | METRO1 | Charles, St. Mary's County, MD | Maryland | Charles, St. Mary's |
| Potomac Electric Power Company | DCPEP | Washington DC Area | Maryland | Washington DC Area |
| RCN Telecom LLC | RCNMD | Montgomery County - Silver Spring, Gaithersburg, Takoma Park, Chevy Chase, Bethesda ,Wheaton. langley Park | Maryland | Montgomery |
| Southern Maryland Electric Cooperative | SMECO1 | Southern Maryland | Maryland | Calvert, Charles, Prince George's, St. Mary's |
| Southern Maryland Electric Cooperative | SMECO2 | Southern Maryland | Maryland | Calvert, Charles, St. Mary's |
| State of Maryland Dept of IT | DOITMD | State of Maryland | Maryland | Calvert, Charles, Prince George's, St. Mary's |
| Think Big Networks, LLC | TNKBIG | Charles County, MD | Maryland | Charles |
| Verizon Maryland | VZBMET | Verizon Baltimore Metro (Harford, Baltimore County, Baltimore City, Howard, Anne Arundel, Carroll) | Maryland | Anne Arundel, Baltimore, Baltimore City, Carroll, Harford, Howard |
| Verizon Maryland | VZMES | Verizon Maryland Eastern Shore (Caroline, Cecil, Dorchester, Harford, Kent, Queen Anne’s, Queenstown, Somerset, Stevensville, Talbot, Wicomico, Worcester) | Maryland | Caroline, Cecil, Dorchester, Harford, Kent, Queen Anne's, Somerset, Talbot, Wicomico, Worcester |
| Verizon Maryland | VZWMD | Verizon Western Maryland (Garrett, Washington, Frederick, Alleghany, Carroll) | Maryland | Allegany, Carroll, Frederick, Garrett, Washington |
| Verizon Maryland | VZWSAM | Verizon MD (DC suburbs) (Prince George's, Montgomery) | Maryland | Montgomery, Prince George's |
| Verizon Maryland LLC | VZSMCO | Southern Maryland used by SMECO | Maryland | Calvert, Charles, Prince George's, St. Mary's |