North American Numbers Source-cited · ownership disclosed
Area code
227
In service
United States · since 2023

Western/Southern Maryland (overlay)

The newest Maryland area code, a distributed overlay of the 301/240 region in western and southern Maryland. It went into service June 14, 2023.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Western/Southern Maryland (overlay)
Type
geographic
Status
in service
In service since
2023
Projected exhaust
2041 Q1

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 227 is

Western and southern Maryland: same footprint as 301/240 — Allegany, Charles, Garrett, Montgomery, Prince George's, St. Mary's and Washington counties; most of Frederick; western Howard; and slivers of Carroll and Anne Arundel..

Communities served wholly or partly by 227:

Silver SpringRockvilleBethesdaGaithersburgGermantownFrederickHagerstownCumberlandWaldorf

Same geography as 301 and 240 — an overlay, not a distinct area.

B · Relationships

How it relates to other codes

The codes 227 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Overlay · 2023 301 Western/Southern Maryland (D.C. suburbs) 227 overlays the 301 base code.
Overlay · 2023 240 Western/Southern Maryland (overlay) 227 overlays 240 as well; all three share the region.
Related · 1991 410 Baltimore The 301 region 227 overlays originally spawned 410 for eastern Maryland.
What's changing. Newest overlay of the 301/240/227 complex; ten-digit dialing mandatory. 2023 activation — re-check NANPA for latest status.
C · History

How 227 got here

2001-01-03
Area code 227 approved as an all-services distributed overlay, held in reserve until needed.
Source: Wikipedia
2023-06-14
Area code 227 went into service as a third overlay of the 301/240 region. (re-check NANPA)
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
152
Prefixes available
648
Thousands-blocks assigned
1,176

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 227 with another code →
Sources
Wikipedia ↗
Area code 227
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.