227
Area code

MD

United States geographic area code, in service since 2023-06-14. Part of the 227/240/301 overlay complex — ten-digit dialing required.

Split from 301. Overlaid with 240 .

Statusin service
Introduced2023-06-14
JurisdictionMD, US
Local dialing10D
Time zoneEastern
Last verified2026-09-17
Utilization 19.2% of assignable prefixes assigned As of 09/17/2026
0%152 of ~792 assignable NXX values (200–999 excl. N11)100%

Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2023-07-27, most recent 2026-09-04.

Area codes serve rate-center geographies, not municipal boundaries. “MD” identifies the jurisdiction, not an exact city footprint.

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier
Largest initial assignees in area code 227
RankAssigneePrefixesShare
01 ONVOY, LLC - MD 38 25%
02 NEW CINGULAR WIRELESS PCS, LLC - DC 37 24.3%
03 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 22 14.5%
04 MULTIPLE OCN LISTING 9 5.9%
05 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 9 5.9%
06 COMMIO, LLC 7 4.6%
07 WIDE VOICE, LLC - MD 5 3.3%
08 ONVOY SPECTRUM, LLC 5 3.3%
09 BANDWIDTH.COM CLEC, LLC - MD 5 3.3%
10 5 3.3%

Important: these are initial assignees from NANPA CO-code records — the carrier a prefix was originally assigned to. Because of number portability, the current serving carrier of any individual number may differ.

Change history

Recorded events for this NPA

Planning letters & orders

Primary documents
NANPA planning letters for area code 227
DateDocumentSubject
2022-09-27 PL-603 ↗ NPA 227 to Overlay NPA 240/301 (Maryland)

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