Maryland Area Codes
Compare 6 in-service area codes assigned to Maryland. Explore each code’s introduction date, overlays, possible time zones, and public prefix records.
Maryland numbering at a glance
- In-service area codes
- 6
- Time-zone labels in NANPA data
- Eastern
- Listed in-service or assigned prefixes
- 3,705 · source dated 2026-09-29
These are numbering assignments. The counts do not represent active phone numbers, current carriers, or a caller’s physical location.
Compare area codes in Maryland
| Code | Introduced | Other codes in overlay | Time zones | Listed prefixes |
|---|---|---|---|---|
| 227 | 14-Jun-2023 | 240, 301 | Eastern | 128 |
| 240 | 01-Jun-1997 | 227, 301 | Eastern | 785 |
| 301 | 01-Jan-1947 | 240, 227 | Eastern | 784 |
| 410 | 06-Oct-1991 | 443, 667 | Eastern | 783 |
| 443 | 01-Jun-1997 | 410, 667 | Eastern | 785 |
| 667 | 24-Mar-2012 | 410, 443 | Eastern | 440 |
Source: NANPA NPA database, dated 2026-09-28. Prefix counts: NANPA US assignment report. View official area-code maps.
Overlay groups in Maryland
Codes in an overlay group can serve the same broad numbering area. A person may keep a number after moving, and the displayed number may be spoofed.
Find a number in Maryland
Open an area-code page above to check a prefix and possible time zones. You can also search US telephone rate-center names; those names are not exact city coverage.
A code cannot verify the owner of a number. If an unexpected caller asks for money or sensitive information, verify the claim independently.