All 6 Maryland Area Codes
Every active code: tap any card for its full guide, who called, cities and ZIPs, map, spam patterns and local time.
Why Metro Baltimore Has 6 Area Codes
When a region uses more numbers than one code can hold, new codes are overlaid on the same territory rather than forcing anyone to change numbers. Metro Baltimore now uses 227, 240, 301, 410, 443 and 667: same neighborhoods, ten-digit dialing, and every one of them covered by its own guide above.
Maryland Area Codes by City
The largest Maryland communities and the area codes that serve them. Every city links to its local AT&T internet page.
How Maryland Got Its Codes
Every Maryland area code, in the order it entered service. Splits carved new regions; added codes overlay existing ones, which is why ten-digit dialing is standard.
| In service | Code | How it arrived |
|---|---|---|
| 1947 | 301 | One of the original area codes of 1947 |
| 1991 | 410 | Added to the 301 region |
| 1997 | 240 | Added to the 301 region |
| 1997 | 443 | Added to the 410 region |
| 2012 | 667 | Added to the 443 region |
| 2023 | 227 | Added to the 301 region |
Source: NANPA NPA database, July 2026. Regenerated monthly.
Maryland Area Code Map
Every active Maryland area code at a glance, anchored to the metro each one serves. Tap any code above for its detailed coverage map.
↓ Printable PDFOpen the printable Maryland area code map (PDF) — poster format with a QR code back to this page.
Internet, wireless & stores across the state
AT&T Home Internet in Maryland
AT&T home internet is available across Maryland, checked address by address; every area code guide above lists its cities and what’s offered there.
AT&T Fiber: Ltd. avail/areas. Speeds based on wired connection. Actual speeds vary. For 5-GIG, single device wired speed maximum 4.7Gbps. For more info., visit att.com/speed101.
Start with home internet in Maryland, or pair it with wireless in an internet + wireless bundle.
AT&T Wireless in Maryland
AT&T’s 5G network covers most of Maryland. ActiveArmor® spam blocking is included with every unlimited plan, your number stays yours when you move between Maryland codes, and great cell phone deals in Maryland are a tap away.
AT&T may temporarily slow data speeds if the network is busy. 5G req’s compatible plan & device. Coverage not available everywhere. Learn more at att.com/5Gforyou.
AT&T Stores Across Maryland
From the Baltimore metro to Hanover, Columbia and beyond, walk in for switching, porting, upgrades and hands-on help. Every area code guide lists its nearest stores.
Find stores in: Baltimore · Hanover · Columbia · Hagerstown · Bowie
