Maryland area codes
6 area codes currently serve Maryland. The state's numbering history begins in 1947 with 301. Most recent addition: 227, in service since 2023.
Coverage runs through 240 (Washington), 443 (Baltimore), 301 (Washington), 410 (Baltimore), 667 (Baltimore), 227 (Washington); prefix counts in the table approximate each code's numbering footprint.
Overlay territory: 227/240/301, 410/443/667 — same geography, several codes, ten-digit local dialing.
Recent numbering history: 667 arrived in 2012, 227 arrived in 2023 — overlays added as existing codes approached exhaust.
Time zone is uniform across the state's codes: Eastern.
227 has served Washington since 2023, carries 121 active prefixes across 37 rate centers, split among 15 carriers. 121 of its prefixes are pooled — shared between carriers in thousands-number blocks. NANPA projects its capacity to last until 1Q 2041 — no relief needed for decades. It was created from 301. Local dialing is ten digits.
240, in service since 1997, anchors Washington, carries 785 active prefixes across 63 rate centers, split among 44 carriers. 727 of its prefixes are pooled — shared between carriers in thousands-number blocks. NANPA projects its capacity to last until 1Q 2041 — no relief needed for decades. It was created from 301. Local dialing is ten digits.
301 has served Washington since 1947, carries 784 active prefixes across 64 rate centers, split among 31 carriers. 397 of its prefixes are pooled — shared between carriers in thousands-number blocks. It is the oldest area code in Maryland, in service since 1947. NANPA projects its capacity to last until 1Q 2041 — no relief needed for decades. Local dialing is ten digits.
410, in service since 1991, anchors Baltimore, carries 783 active prefixes across 102 rate centers, split among 27 carriers. 377 of its prefixes are pooled — shared between carriers in thousands-number blocks. It is covers more rate centers (102) than any other Maryland area code. NANPA projects its capacity to last until 1Q 2036. It was created from 301. Local dialing is ten digits.
443 has served Baltimore since 1997, carries 785 active prefixes across 81 rate centers, split among 26 carriers. 701 of its prefixes are pooled — shared between carriers in thousands-number blocks. NANPA projects its capacity to last until 1Q 2036. It was created from 410. Local dialing is ten digits.
667 has served Baltimore since 2012, carries 433 active prefixes across 102 rate centers, split among 47 carriers. 433 of its prefixes are pooled — shared between carriers in thousands-number blocks. NANPA projects its capacity to last until 1Q 2036. It was created from 443. Local dialing is ten digits.
Toll-free callers are a separate story: 800-family numbers carry no Maryland geography at all, so an 833 or 877 number is never "from" the state — it belongs to whichever business rents it, anywhere in the NANP.
A number in any of these codes was issued in Maryland, but portability means its owner may be anywhere today — the codes locate numbers, not people. To dig further, open a code's prefix or cities pages.
| Code | Major area | In service | Overlay complex | Prefixes |
|---|---|---|---|---|
| 227 | Washington | 2023 | 227/240/301 | 121 |
| 240 | Washington | 1997 | 227/240/301 | 785 |
| 301 | Washington | 1947 | 227/240/301 | 784 |
| 410 | Baltimore | 1991 | 410/443/667 | 783 |
| 443 | Baltimore | 1997 | 410/443/667 | 785 |
| 667 | Baltimore | 2012 | 410/443/667 | 433 |
FAQ
How many area codes does Maryland have?
6 geographic area codes are currently in service: 227, 240, 301, 410, 443, 667.
What was Maryland's first area code?
301, in service since 1947.
Will Maryland get a new area code soon?
Not soon. The earliest exhaust forecast in the state is 410 at 1Q 2036, so current codes have ample capacity.
Which time zone are Maryland numbers in?
All Maryland area codes are in the Eastern time zone.