| Antietam Broadband LLC | ANTMBB | Washington County | Maryland | Washington |
| City of Gaithersburg | CYGRBG | Montgomery County | Maryland | Montgomery |
| Comcast Maryland | COMFCW | Frederick, Carroll, Washington counties in MD | Maryland | Carroll, Frederick, Washington |
| 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 |
| Comcast Maryland | COMWC | Hagerstown MD, Washington County | Maryland | Washington |
| DQE Communications | DQEMD | MD, Washington County | Maryland | Washington |
| Everstream Solutions LLC | EVRSMD | Washington County/Hagerstown | Maryland | Washington |
| Lumos Networks (Segra) | LNWCMD | Washington County | Maryland | Washington |
| MetroCast Communications | METRO1 | Charles, St. Mary's County, MD | Maryland | Charles, St. Mary's |
| NAVFAC | NAVFAC | Charles County, MD | Maryland | Charles |
| Point Broadband Fiber Holding LLC | PTBBMD | Washington county | Maryland | Washington |
| Potomac Electric Power Company | DCPEP | Washington DC Area | Maryland | Washington DC Area |
| RCN Telecom LLC (Astound) | RCNMD | Montgomery County - Silver Spring, Gaithersburg, Takoma Park, Chevy Chase, Bethesda ,Wheaton, Langley Park
Anne Arundel county | Maryland | Anne Arundel, Montgomery |
| Shenandoah Cable Television | SCTMD | Frederick County | Maryland | Frederick |
| Shenandoah Cable Television, LLC | SCTVMD | Formerly Shentel Communications, LLC /Shenandoah Network Company areas: Frederick, Garrett and Washington Counties | Maryland | Frederick, Garrett, Washington |
| 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 | Allegany, Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Charles, Dorchester, Frederick, Garrett, Harford, Howard, Kent, Montgomery, Prince George's, Queen Anne's, Somerset, St. Mary's, Talbot, Washington, Washington DC Area, Wicomico, Worcester |
| The Hagerstown Light Department | HGRTWN | Hagerstown Maryland | Maryland | Washington |
| 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 |