Area Code 410
Maryland
Area code 410 serves Maryland, primarily Baltimore, in the Eastern Time (ET) time zone. It has served the region since 06-Oct-1991.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 443 (Baltimore).
In service since: 06-Oct-1991
Demographics & Economics
- Total Population
- 4,332,726
- Population Density
- 610 people/sq miabove U.S. average (U.S.: 93 people/sq mi)
- Median Household Income
- $90,904above U.S. median (U.S.: $75,144)
- Poverty Rate
- 10.9%near U.S. average (U.S.: 11.5%)
- Unemployment Rate
- 4.9%above U.S. average (U.S.: 3.6%)
- Education Attainment
- Bachelor's Degree+40.5%above U.S. average (U.S.: 33.7%)High School or Lower28.4%
Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.
See how this area code compares to all US area codes in the income ranking and density ranking.
Time Zone
- Eastern Time (ET)
NANPA Relief Status
According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.
Source: NANPA NPA Relief Planning Reports · See all relief planning statuses
Current Time
Prefix Utilization
Geographic Coverage
State
MD
Major Cities
- Baltimore
- Columbia
- Ellicott City
- Glen Burnie
- Dundalk
- Severn
- Bel Air South
- Towson
- Odenton
- Catonsville
- Annapolis
- Essex
- Severna Park
- Randallstown
- Owings Mills
- Pikesville
- Salisbury
- Pasadena
- Milford Mill
- Middle River
- Bel Air North
- Eldersburg
- Parkville
- Crofton
and 195 more cities
Historical Timeline of Area Code 410
Area code 410 was created on October 6, 1991, as a split from area code 301, Maryland's sole area code since the North American Numbering Plan began in 1947. The split separated the Baltimore metropolitan area and the Eastern Shore from western Maryland, where area code 301 was retained to preserve existing federal agency numbers near Washington, D.C. Source: Wikipedia
Key milestones:
- 1947: Maryland assigned sole area code 301 as part of the original 86 North American area codes (Source: Wikipedia)
- 1990: Bell Atlantic (now Verizon) announced plan to split 301 due to rapid growth in Baltimore and Washington suburbs (Source: TelecomRouting)
- 1991: Area code 410 entered service on October 6 with permissive dialing; mandatory 10-digit dialing enforced statewide November 1, 1991 (Source: Wikipedia)
- 1997: Area code 443 overlaid on 410 territory on July 1 to address number exhaustion from cell phones and pagers (Source: Wikipedia)
- 2012: Area code 667 overlaid on 410/443 territory on March 24, adding 24 million possible numbers (Source: TelecomRouting)
- 2030: Projected exhaustion of 410/443/667 numbering pool, requiring a fourth area code (Source: AreaCodes.com)
The 1991 split was driven by the explosive growth of pagers and early mobile phones in the Baltimore region. Western Maryland retained area code 301, and area code 240 was later added as an overlay for that region in 1997.
Regulatory History
Area code 410 has been shaped by four major regulatory decisions over 35 years, beginning with the 1990 Bell Atlantic filing that split Maryland's sole area code and culminating in the 2012 overlay that added area code 667. Source: Wikipedia
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 1990 | Bell Atlantic 301 Split Filing | Bell Atlantic Filing | Bell Atlantic petitioned to split 301 into two codes. Western Maryland retained 301 to preserve federal agency numbers near Washington; Baltimore and the Eastern Shore received 410. (Source: TelecomRouting) |
| 1991 | 410 Service Commencement | NANPA Implementation | Area code 410 entered service October 6 with permissive dialing. Mandatory 10-digit dialing enforced statewide November 1, 1991, requiring all Maryland residents to include the area code for local calls. (Source: Wikipedia) |
| 1997 | 443 Overlay Approved | FCC 98-184 | The FCC approved the 443 overlay on July 1, 1997. Verizon advocated an overlay rather than a second split to avoid forced renumbering for 1.2 million existing 410 subscribers. (Source: Wikipedia) |
| 2012 | 667 Overlay Assigned | NANPA Assignment | Area code 667 added as the third code for the region on March 24, 2012, providing 24 million additional numbers. Projected to sustain the region until approximately 2030. (Source: AreaCodes.com) |
The 1997 overlay was among the early uses of the overlay concept in the mid-Atlantic, establishing a precedent for avoiding forced number changes in densely populated regions. All three codes (410, 443, 667) now share the same geographic territory with mandatory 1+10-digit dialing.
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 410).
| County | Population | Share |
|---|---|---|
| Baltimore, MD | 1,222,634 | 28.2% |
| Baltimore city, MD | 998,461 | 23.0% |
| Anne Arundel, MD | 638,570 | 14.7% |
| Howard, MD | 314,714 | 7.3% |
| Harford, MD | 278,258 | 6.4% |
| Carroll, MD | 211,304 | 4.9% |
| Wicomico, MD | 105,474 | 2.4% |
| Cecil, MD | 104,366 | 2.4% |
| Worcester, MD | 95,422 | 2.2% |
| Calvert, MD | 88,995 | 2.1% |
| Queen Anne's, MD | 66,003 | 1.5% |
| Dorchester, MD | 42,345 | 1.0% |
| Talbot, MD | 38,649 | 0.9% |
| Caroline, MD | 36,137 | 0.8% |
| Somerset, MD | 33,104 | 0.8% |
| Kent, MD | 24,053 | 0.6% |
| Frederick, MD | 22,188 | 0.5% |
| Montgomery, MD | 8,772 | 0.2% |
| Sussex, DE | 1,847 | 0.0% |
| New Castle, DE | 1,430 | 0.0% |
Area Code 410 Family Tree
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All Descendants
Area code 410 was originally assigned in 06-Oct-1991 to serve MD. Over the years, it has generated 2 descendant area codes through a combination of geographic splits and overlays as demand for telephone numbers grew.
Call Context
This area code covers a metropolitan region in MD with moderate to high population density, centered on Baltimore and surrounding communities.
Nearby Area Codes
Area codes geographically closest to 410.
Other Area Codes in Maryland
Area codes that also serve Maryland, linked for easy comparison.