Area Code 443
Maryland
Area code 443 serves Maryland, primarily Baltimore, in the Eastern Time (ET) time zone. It is an overlay area code sharing territory with area code 410.
Published: Last reviewed: Verified against NANPA and FCC records
Overlay Area Code
This area code shares its geographic footprint with an overlay code, so the same cities are served by two area codes. Because overlays leave existing numbers untouched, this region's relief planning favors adding codes over redrawing boundaries.
The codes serving this same region: area code 667 (Baltimore).
With prefix utilization already at 98.1%, numbering resources here are under sustained pressure — context that explains why overlays were introduced.
In service since: 01-Jun-1997
Demographics & Economics
- Total Population
- 4,332,726
- Population Density
- 614 people/sq miabove U.S. average (U.S.: 95 people/sq mi)
- Median Household Income
- $91,768above U.S. median (U.S.: $80,734)
- Poverty Rate
- 10.8%below U.S. average (U.S.: 12.5%)
- Unemployment Rate
- 4.9%near U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+41.2%above U.S. average (U.S.: 35.7%)High School or Lower28.1%
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 443
Area code 443 is a Maryland area code that entered service on June 1, 1997, as an all-services overlay of area code 410. The code serves the Baltimore metropolitan area, the state capital Annapolis, and the Chesapeake Bay communities of Maryland's Eastern Shore, including Baltimore, Columbia, Towson, Bel Air, Salisbury, and Westminster. NANPA assigned 443 on June 21, 1996 as a future relief overlay, and the code entered service on the same day as area code 240 — the two codes that introduced overlay numbering to Maryland. Source: NANPA
Key milestones:
- 1991: On October 6, area code 410 was created by a geographic split of area code 301, one of the original 77 US NANP area codes. The split established a separate numbering plan area for the Baltimore metropolitan region and the Eastern Shore. Source: NANPA
- 1996: On June 21, NANPA assigned area code 443 as a future all-services overlay of area code 410, providing number-relief capacity for continued growth in Baltimore's suburbs and rising wireless and second-line demand. Source: NANPA
- 1997: On June 1, area code 443 entered service. New telephone numbers in the 410 territory could now be assigned under either the 410 or the 443 prefix. Source: NANPA
- 2012: On March 24, area code 667 entered service as a second all-services overlay over the 410/443 territory, completing the 410/443/667 overlay complex. Source: NANPA
Regulatory History
The regulatory history of area code 443 begins with the 1991 split that created area code 410, continues through NANPA's 1996 overlay assignment and the June 1, 1997 in-service date, and extends to the 2012 activation of area code 667 that completed the 410/443/667 overlay complex. Source: NANPA
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 1991 | 410 split from 301 | Maryland PSC / NANPA | Area code 410 was created on October 6, 1991 as a geographic split of area code 301, one of the original 77 US NANP area codes. The split established a separate numbering plan area for the Baltimore metropolitan region and the Eastern Shore. Source: NANPA |
| 1996 | 443 assigned as overlay | NANPA assignment | NANPA assigned area code 443 on June 21, 1996 as a future all-services overlay of area code 410, providing number-relief capacity for the Baltimore region's growing wireless and second-line demand. Source: NANPA |
| 1997 | 443 enters service | NANPA / Maryland PSC | Area code 443 entered service on June 1, 1997, the same day as area code 240, making them Maryland's first two overlays. New numbers in the 410 territory could be assigned under either prefix. Source: NANPA |
| 2012 | 667 second overlay activated | NANPA planning letters | Area code 667 entered service on March 24, 2012 as a second all-services overlay over the 410/443 territory, completing the 410/443/667 overlay complex and extending relief capacity across the region. Source: NANPA Planning Letters |
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 443).
| 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 443 Family Tree
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Area code 443 was originally assigned in 01-Jun-1997 to serve MD. Over the years, it has generated 1 descendant area code through a combination of geographic splits and overlays as demand for telephone numbers grew.
Call Context
This area code covers a geographic region across MD, including Baltimore and surrounding communities.
Nearby Area Codes
Area codes geographically closest to 443.
Other Area Codes in Maryland
Area codes that also serve Maryland, linked for easy comparison.