| District of Maryland area codes: 443 | |
|---|---|
| Country | United States |
| State/Province | Maryland |
| Major City | Baltimore |
| Time Zone | Eastern |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 443-342 | Calvert | Solomons, MD | Ctc Communications Corp. |
| 443-343 | Anne Arundel | Millersville, MD | Teleport Communications America |
| 443-344 | Anne Arundel | Severna Park, MD | Core Communications |
| 443-345 | Harford | Aberdeen, MD | Level 3 Communications |
| 443-346 | Anne Arundel | Severna Park, MD | Xo Maryland |
| 443-347 | Harford | Cardiff, MD | Ctc Communications Corp. |
| 443-348 | Baltimore City | Baltimore, MD | Teleport Communications America |
| 443-349 | Carroll | Westminster, MD | Core Communications |
| 443-350 | Cecil | Elkton, MD | Cellco Partnership DBA Verizon Wireless |
| 443-351 | Howard | Columbia, MD | Us Lec Of Maryland |
| 443-352 | Baltimore City | Baltimore, MD | AT&T Local |
| 443-353 | Baltimore | Cockeysville, MD | Verizon Maryland |
| 443-354 | Baltimore City | Baltimore, MD | Level 3 Communications |
| 443-355 | Baltimore City | Baltimore, MD | Level 3 Communications |
| 443-356 | Harford | Bel Air, MD | Level 3 Communications |
| 443-357 | Baltimore | Pikesville, MD | Verizon Maryland |
| 443-358 | Wicomico | Salisbury, MD | Ymax Communications Corp. |
| 443-359 | Wicomico | Delmar, MD | Cellco Partnership DBA Verizon Wireless |
| 443-360 | Harford | Aberdeen, MD | Teleport Communications America |
| 443-361 | Carroll | Sykesville, MD | Core Communications |
There are 781 prefixes, In the code area, the major cities are Annapolis, MD;Arbutus, MD;Arnold, MD;Baltimore, MD. The major city is Baltimore.