| 667-203 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-205 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-206 | Towson, MD | Wireless | Metro PCS |
| 667-207 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-208 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-209 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-210 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-212 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-213 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-214 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-216 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-217 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-218 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-219 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-224 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-225 | Maryland (MD) | Wireless | New Cingular Wireless PCS - DC |
| 667-228 | Omnipoint Communications Cap Operations, Llc | Wireless | Baltimore |
| 667-231 | Aberdeen, MD | Landline | Xo Maryland |
| 667-233 | Verizon Maryland, Inc. | Landline | Baltimore |
| 667-234 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-239 | Baltimore, MD | Wireless | Cellco Partnership DBA Verizon Wireless |
| 667-251 | Level 3 Communications, Llc - Md | Landline | Baltimore |
| 667-253 | Salisbury, MD | Wireless | 365 Wireless |
| 667-260 | Citrix Communications Llc - Md | Landline | Baltimore |
| 667-303 | Baltimore, MD | Wireless | 365 Wireless |
| 667-305 | Pikesville, MD | Wireless | 365 Wireless |
| 667-307 | Crofton, MD | Landline | Peerless Network Of Maryland |
| 667-308 | Baltimore, MD | Landline | Peerless Network Of Maryland |
| 667-309 | Baltimore, MD | Landline | Local Access LLC |
| 667-312 | Atlantech Online, Inc. - Md | Landline | Baltimore |
| 667-330 | Salisbury, MD | Landline | Us Lec Of Maryland |
| 667-367 | Baltimore-washington Telephone (bwt) | Landline | Baltimore |
| 667-401 | Baltimore, MD | Landline | Level 3 Communications |
| 667-444 | Neutral Tandem-maryland, Llc - Md | - | Baltimore |
| 667-600 | Worldcall Interconnect Inc. | - | Baltimore |
| 667-677 | Broadvox-clec, Llc - Md | Landline | Baltimore |
| 667-770 | Airus, Inc. - Md | - | Baltimore |
| 667-777 | Maryland (MD) | Landline | Peerless Network Of Maryland |
| 667-802 | Omnipoint Communications Cap Operations, Llc | Wireless | Baltimore |
| 667-803 | Solomons, MD | Landline | Bandwidth.com Clec |
| 667-888 | Voxbeam Telecommunications Inc. - Md | Landline | Baltimore |
| 667-930 | Rclec, Inc. - Md | Landline | Baltimore |
| 667-999 | Neutral Tandem-maryland, Llc - Md | Landline | Baltimore |