View source for Area codes 301, 240, and 227

{{Short description|North American telephone area codes in Western Maryland, U.S.}}
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image:Area code 301.svg|right|300px|thumb|alt=area codes 227, 240, and 301. These numbers are related to the main zip codes of Maryland.|Maryland consists of the red and blue areas. The red area has area codes 227, 240 and 301.
poly 336 37 323 30 310 13 305 -2 337 2 [[Area codes 215, 267, and 445]]
poly 339 121 325 118 296 86 296 73 307 56 319 51 328 48 327 42 337 34 [[Area code 856]]
poly 248 1 257 11 265 35 253 43 264 50 258 64 278 67 286 56 294 54 305 58 328 47 324 41 335 35 322 30 304 -2 [[Area codes 610, 484, and 835|Area code 484]]
poly 85 65 88 53 101 43 109 48 111 33 100 12 94 4 100 -1 245 -1 258 12 266 35 250 43 263 50 256 66 [[Area code 717]]
poly 36 1 43 9 38 19 37 29 17 44 14 67 84 66 87 53 101 44 106 48 111 35 96 5 96 -1 [[Area code 814]]
poly 2 2 0 65 16 68 18 43 39 30 40 17 45 10 35 2 [[Area code 724]]
poly 181 143 184 134 195 144 186 156 184 147 182 142 [[Area code 202]]
poly 168 182 169 171 177 170 176 165 184 162 184 152 179 139 168 135 171 131 148 123 141 129 148 166 [[Area code 571]]
poly 327 230 290 235 282 236 283 246 317 243 [[Area codes 757 and 948]]
poly 336 153 335 186 288 188 277 69 286 56 294 55 303 57 298 76 299 88 316 129 [[Area code 302]]
poly 337 190 327 226 278 242 235 193 219 187 214 168 211 157 211 135 205 121 201 116 198 109 200 105 173 94 175 86 167 66 275 67 288 188 [[Area codes 410, 443, and 667]]
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poly 247 250 249 239 221 220 214 212 200 213 189 199 184 211 169 211 142 226 121 223 106 243 113 248 [[Area code 804]]
poly 48 250 34 235 60 212 84 208 79 192 77 189 93 172 106 185 122 223 106 243 107 247 [[Area code 434]]
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'''Area codes 301, 240, and 227''' are [[telephone]] [[area code]]s in the [[North American Numbering Plan]] (NANP) for the western part of the [[U.S. state]] of [[Maryland]]. The numbering plan area (NPA) comprises Maryland's portion of the Greater [[Washington, D.C.]] [[Washington metropolitan area|metro area]], portions of [[southern Maryland]], along with rural [[western Maryland]]. This includes the communities of [[Cumberland, Maryland|Cumberland]], [[Frederick, Maryland|Frederick]], [[Hagerstown, Maryland|Hagerstown]], [[Gaithersburg, Maryland|Gaithersburg]], [[Potomac, Maryland|Potomac]], [[Germantown, Maryland|Germantown]], [[Bethesda, Maryland|Bethesda]], [[Rockville, Maryland|Rockville]], [[Landover, Maryland|Landover]], [[Silver Spring, Maryland|Silver Spring]], and [[Waldorf, Maryland|Waldorf]].

Area code 301 was the first area code for all of Maryland, from 1947, when the area code system was created, until 1991, when everything from [[Baltimore]] eastward was split off as [[area code 410]]. In 1997, area code 240 was added as an [[overlay plan|overlay area code]] for the 301 territory. On June 14, 2023, a third overlay code, 227, was added to provide more central office prefixes for new telephone numbers.

==History==
Area code 301 was one of the [[original North American area codes]] when the [[American Telephone and Telegraph Company]] (AT&T) established a new, nationwide [[telephone numbering plan]] in 1947. The area code served the entire state of Maryland.

Much of the [[Washington metropolitan area]] is part of a local calling area which is centered on the District's [[area code 202]], and also extends into the suburban area in southern Maryland with 301 and [[Northern Virginia]] with [[area code 703]]. From 1947 to 1990, it was possible to dial any other telephone number in the metro area as a local call with only seven digits, not using an area code, irrespective of the home area code.  The entire metro area was also reachable via long-distance services by dialing area code 202, for which purpose AT&T had established cross-referenced operator routing codes for all affected central offices. This was implemented via a system of [[central office code protection]], meaning that no central office code in the metro area could exist in more than a single central office. <ref>AT&T Long Lines, ''[http://historyofphonephreaking.org/docs/ddrg/ Distance Dialing Reference Guide]'' (April 1974)</ref> For example, if 202-574 numbers were in use in the District or 703-574 numbers were in use in Northern Virginia, the corresponding 301-574 numbering block could only be assigned in areas considered a safe distance away from the capital, such as the [[Eastern Shore of Maryland]].

===Ten-digit dialing===
By the end of the 1980s, the Washington metropolitan area was running out of assignable prefixes for new central offices on both sides of the [[Potomac River]]. The only unassigned prefixes were unavailable due to the central office code protection that maintained seven-digit dialing in the metro-area. Assignment of these prefixes would require dialing an area code. The three local operating companies of the [[C&P Telephone|Chesapeake and Potomac Telephone Company]] (C&P Telephone, later part of Bell Atlantic and now [[Verizon]]) cooperated in ending code protection for the Washington area on October 1, 1990.  Ten-digit dialing was now required for all local calls between Maryland, the District of Columbia, and Virginia.<ref>"[https://www.newspapers.com/image/376270861/ Area Codes Needed to Call Between Md., D.C., Va.]" ''The Baltimore Sun''. October 1, 1990. p. 2B.</ref> Area code 202 was no longer usable for suburban points. Local calls within Maryland did not require the area code.<ref name= complicated>Jordan, Mary; Quimpo, Margie G. (September 23, 1990). "Territorial Telephones; On Oct. 1, Local Calls Will Get Complicated". ''The Washington Post''. p. 1.</ref> Permissive dialing using the old dialing procedures continued from April 1 through October 1, 1990.<ref>NANPA Bellcore Information Letter IL-90/04-003</ref>

===410-split===
Due to the overall growth of the [[Baltimore–Washington metropolitan area]], it became apparent by the end of the 1980s that terminating central office code protection in the Washington area could not free up sufficient resources north of the [[Potomac River]] to stave off the immediate need for a new area code.

In mitigation action, [[Baltimore]] and the [[Eastern Shore of Maryland|Eastern Shore]] were reassigned from area code 301 to [[area code 410]] on November 1, 1991, to form a new numbering plan area.<ref>Muth, Charlie (November 17, 1990). "[https://www.newspapers.com/image/281595821/ Shore to Get New Area Code]". ''The Daily Times'' (Salisbury, Maryland). p. 1, 4.</ref><ref>Hetrich, Ross (October 25, 1991). "[https://www.newspapers.com/image/367447179/ New Area Code 410 Starts Nov. 1 in Half of State]". ''The Baltimore Evening Sun''. p. C12.</ref> The [[area code split]] largely followed metropolitan area lines with a few exceptions. While [[Howard County, Maryland|Howard County]] is often recognized as part of the Baltimore metropolitan area, a small portion of the county remained in 301, while the rest of the county was reassigned to 410.<ref>{{cite web|title=Bellcore Letter IL-90/12-049 |url= http://www.nationalnanpa.com/pdf/old_pl/IL%2090-12-049.pdf |work= North American Numbering Plan Administration |publisher= Neustar |access-date=June 21, 2013 }}</ref>

When an area code is split, the largest city in the old numbering plan area (in this case Baltimore) typically retains the existing area code to minimize expense for changing telephone numbers. However, Bell Atlantic opted to leave the western half of the state in 301 so as to spare the large number of federal agencies on the Maryland side of the Washington area from the expense and disruption of a new area code. While Maryland would have likely needed another area code due to the growth of the Baltimore-Washington corridor, it is likely that a split would have been delayed had more 301 numbers been available for use in Baltimore.

===240-overlay===
Although the area code split was intended as a long-term solution, within four years 301 was close to exhaustion due to the proliferation of cell phones and pagers, especially in the Washington suburbs. In relief action, area code 240 was introduced on June 1, 1997, to form the state's first [[overlay plan|overlay]].<ref>{{cite web|title=Bellcore Letter IL 96/06-009|url=http://www.nationalnanpa.com/pdf/old_pl/IL%2096-06-009.pdf|work=North American Numbering Plan Administration|publisher=Neustar|access-date=21 June 2013}}</ref>  Overlays were a new concept at the time, and met with some resistance due to the requirement for [[ten-digit dialing]].<ref>Yates, Jennifer C. (April 22, 1997). "[https://www.newspapers.com/image/93401316/ Maryland Gets Read for 10-digit Dialing]". ''Associated Press''. The Star-Democrat (Easton, Maryland). p. A1.</ref> It was decided to create an overlay rather than split the region into two numbering plan areas to avoid assigning a new area code to 1.2{{nbsp}}million existing telephone numbers.<ref>"[https://www.newspapers.com/image/281648338/ Ready for 10-digit Stroll?]". ''The Daily Times'' (Salisbury, Maryland). January 23, 1997. p. 4.</ref> At the time, it was predicted that it would take until 2008 to exhaust area code 240.<ref>Pemberton, Mary (May 2, 1997). "[https://www.newspapers.com/image/46827915/ 10-digit Dialing Comes to Maryland]". ''Associated Press''. The Gettysburg Times (Gettysburg, Pennsylvania). p. A3.</ref>

===227-overlay===
A September 2022 study projected that the 301/240 numbering plan area (NPA) would suffer central office code exhausted between April and June 2023.<ref name="exhaust">{{cite web|url=https://nationalnanpa.com/reports/2022-1_NPA%20Exhaust_Projections.pdf|date=April 21, 2021|publisher=North American Numbering Plan Administrator |title=2022-1 NRUF and NPA Exhaust Analysis|access-date=July 15, 2021}}</ref>
Area code 227 was already approved as an all-services distributed overlay since January 3, 2001 for the 301/240 NPA.<ref>{{cite web
|url=https://www.nationalnanpa.com/planning_letters/PL_603.pdf
|title=Planning Letter PL-603: NPA 227 and 240/301 All-Services Overlay (Maryland)
|publisher=NANPA
|date=2022-09-27
|access-date=2023-05-27
}}</ref><ref name= duffy>Duffy, Ken (September 28, 2022). "[https://www.wbal.com/article/index/585215?title=New-area-code-coming-to-parts-of-Maryland New Area Code Coming to Parts of Maryland]". ''[[WBAL (AM)|WBAL]]''.</ref> The new area code went into service on June 14, 2023, at which time activation of new central office codes could begin, once all assignable central office codes in 240/301 had been exhausted.

==Service area==
The numbering plan area 301/240/227 includes all of [[Allegany County, Maryland|Allegany]], [[Charles County, Maryland|Charles]], [[Garrett County, Maryland|Garrett]], [[Montgomery County, Maryland|Montgomery]], [[Prince George's County, Maryland|Prince George's]], [[Saint Mary's County, Maryland|St. Mary's]] and [[Washington County, Maryland|Washington]] counties, most of [[Frederick County, Maryland|Frederick County]],{{efn|name=split|Four counties were split between area code 301 and 410.
* In Anne Arundel County, [[Laurel, Maryland|Laurel]] exchanges 210, 317, 490, 497, 498, 596, 604, 725, and 778 and [[Upper Marlboro, Maryland|Marlboro]] exchange 952 remained area code 301. The rest of the county was assigned area code 410.
* In Carroll County [[Mount Airy, Maryland|Mount Airy]] exchange 829 remained area code 301. The rest of the county was assigned area code 410.
* In Howard County, Mount Airy exchange 829 and Laurel exchanges 210, 317, 490, 497, 598, 604, 725, and 776 remained area code 301. The rest of the county was assigned area code 410.
* Most of Frederick County remained area code 301. Only [[Union Bridge, Maryland|Union Bridge]] exchange 775 and [[New Windsor, Maryland|New Windsor]] exchange 635 were assigned area code 410.<ref name= newareacode>"New area code for eastern Maryland". ''The Baltimore Sun''. November 1, 1991. p. 1A.</ref> 
}} western [[Howard County, Maryland|Howard County]],{{efn|name=split}} and slivers of southwestern [[Carroll County, Maryland|Carroll County]]{{efn|name=split}} and western [[Anne Arundel County, Maryland|Anne Arundel County]].{{efn|name=split}}

Local calls require ten-digit dialing (area code + number, leading "1" is not required). Some areas, such as [[Rockville, Maryland|Rockville]],<ref>[https://www.localcallingguide.com/lca_exch.php?dir=&exch=080620 Local calling guide: Washington Zone 10, MD]</ref> [[Gaithersburg, Maryland|Gaithersburg]],<ref>[https://www.localcallingguide.com/lca_exch.php?dir=&exch=079700 Local calling guide: Gaithersburg, MD]</ref> [[Upper Marlboro, Maryland|Upper Marlboro]],<ref>[https://www.localcallingguide.com/lca_exch.php?dir=&exch=080670 Local calling guide: Washington Zone 15, MD]</ref> [[Bethesda, Maryland|Bethesda]]<ref>[https://www.localcallingguide.com/lca_exch.php?dir=&exch=080570 Local calling guide: Washington Zone 2, MD]</ref> and [[Landover, Maryland|Landover]] in Maryland<ref>[https://www.localcallingguide.com/lca_exch.php?dir=&exch=080590 Local calling guide: Washington Zone 4, MD]</ref> remain a local call to the District and Northern Virginia.

==Notes==
{{notelist}}

==References==
{{reflist}}

==External links==
{{Area_code_footer|Map=MD}}
*[https://npnr.org/301/ 301 Area Code in Maryland]
*[https://npnr.org/240/ 240 Area Code in Maryland]

{{clear}}

{{Area code box|State=MD|
| This=area codes 301/240/227
| N=[[area codes 717 and 223|717/223]], [[area code 412|412]]/[[area code 724|724]]/[[area code 878|878]], [[area codes 814 and 582|814/582]]
| S=[[area codes 804 and 686|804/686]], [[area codes 304 and 681|304/681]]
| E=[[Area codes 410, 443, and 667|410/443/667]]
| W=[[area codes 202 and 771|202/771]], [[area codes 304 and 681|304/681]], [[area codes 540 and 826|540/826]], [[area codes 703 and 571|703/571]]
| S1=DC | S2=PA | S3=VA | S4=WV
}}

{{DEFAULTSORT:Area codes 227 240 301}}
[[Category:Area codes in the United States|227 240 301]]
[[Category:Area codes in Maryland|301]]
[[Category:Telecommunications-related introductions in 1947]]
[[Category:Telecommunications-related introductions in 1997]]
[[Category:Telecommunications-related introductions in 2023]]