Postal Codes

21821 ZIP Code

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ZIP code 21821 covers Deal Island, Maryland, with a population of about 736 and a median household income of $51,500.

Population
73650 per square mile
Median age
56.517.8 points above the US average
Median household income
$51,50049% below the Maryland median
Poverty rate
15.4%3 points above the US average
Typical home value
$208,477up 22.3% in five years
Median rent
$1,35618% below the Maryland median
Degree or higher
8.4%26.6 points below the US average
Homeownership
89.8%24.8 points above the US average
Time zone
Eastern UTC-05:00observes daylight saving time
Businesses
9

Where 21821 is

Deal Island, Maryland — the area the Census Bureau draws for this ZIP code. ZIP codes are sets of delivery routes rather than areas, so this is the Census approximation of one, not a Postal Service boundary.

People and households

American Community Survey 2019–2023 five-year estimates

Population736
Median age56.5
Family households54.4%
Born outside the US6%
Speaks a language other than English at home5.1%
White (non-Hispanic)90.9%
Black (non-Hispanic)4.3%
Asian (non-Hispanic)0%
Hispanic or Latino4.5%
Veterans7.9%
Population by age
MaleFemale0-45-910-1415-1920-2425-3435-4445-5455-6465-7475-8485+
Income and poverty

American Community Survey 2019–2023 five-year estimates

Median household income$51,500
Income per person$30,218
Poverty rate15.4%
Households on SNAP or cash assistance19.9%

Household income distribution

Under $10k6.1%
$10–15k9.4%
$15–20k0.0%
$20–25k13.2%
$25–30k4.1%
$30–35k8.2%
$35–40k0.9%
$40–45k6.4%
$45–50k0.9%
$50–60k5.0%
$60–75k19.0%
$75–100k5.0%
$100–125k13.5%
$125–150k3.2%
$150–200k3.5%
$200k or more1.8%

Income as declared to the IRS

Filed returns rather than survey responses, so this counts tax units and not households.

Tax returns filed370
Mean adjusted gross income$69,943
Returns declaring $200,000 or more0%
Returns, under $25k29.7%
Returns, $25k–$50k27.0%
Returns, $50k–$75k13.5%
Returns, $75k–$100k10.8%
Returns, $100k–$200k18.9%
Returns, $200k or more0.0%
Housing

American Community Survey 2019–2023 five-year estimates

Median home value$151,700
Median gross rent$1,356
Owner-occupied89.8%
Vacant homes50.8%
Median year built1965

What the homes are

Detached house87.3%
Attached house2.2%
Mobile home10.5%
Home values and rents today

Zillow Home Value Index and Zillow Observed Rent Index, courtesy of Zillow. Monthly and current, where the Census figures above are a five-year average and are capped at $2,000,000.

Typical home value$208,477as of 2026-07
Typical home value, 1 yearup 3.6%
Typical home value, 5 yearsup 22.3%
Typical home value, 10 yearsup 70.7%
Typical home value since 2000
200020132026$208,477$78,490

$78,490 in 2000 to $208,477 in 2026.

Work, commuting and education

American Community Survey 2019–2023 five-year estimates

Unemployment rate1.9%
Bachelor's degree or higher8.4%
High school diploma or higher86.1%
Works from home8%
Drives to work alone44.5%
Takes public transport0%
Commutes 45 minutes or more24.2%
Health

CDC PLACES 2025 release, model-based estimates. These are modelled small-area estimates for adults, not counts of diagnosed cases.

Obesity34.9% 1.5 pts above the national average of 33.4%
Diagnosed diabetes17.3% 5.3 pts above the national average of 12%
Currently smokes17.2% 4 pts above the national average of 13.2%
High blood pressure51% 16.9 pts above the national average of 34.1%
Fair or poor general health24.8% 4.5 pts above the national average of 20.3%
No health insurance (18–64)9% 2.3 pts below the national average of 11.3%
Depression20.9% 1 pts below the national average of 21.9%
No leisure-time physical activity32.7% 7.3 pts above the national average of 25.4%
Arthritis41.6% 16.5 pts above the national average of 25.1%
Binge drinking12.4% 3.6 pts below the national average of 16%
Taking blood pressure medication83.4% 8.7 pts above the national average of 74.7%
Cancer (non-skin)13.4% 5.7 pts above the national average of 7.7%
Current asthma11% 0.6 pts above the national average of 10.4%
Coronary heart disease11.9% 5.7 pts above the national average of 6.2%
Routine check-up in past year83.1% 6.4 pts above the national average of 76.7%
Cholesterol screening91.4% 5.5 pts above the national average of 85.9%
Cognitive disability14.5% same as the national average of 14.8%
Colorectal screening74% 9.7 pts above the national average of 64.3%
COPD12.4% 5.8 pts above the national average of 6.6%
Visited a dentist61% same as the national average of 61.3%
Any disability37.8% 7.1 pts above the national average of 30.7%
Lacks emotional support24.1% 0.7 pts below the national average of 24.8%
Food insecurity14.5% 2.6 pts below the national average of 17.1%
Received food stamps12.6% 1.7 pts below the national average of 14.3%
Hearing disability11.5% 4.8 pts above the national average of 6.7%
High cholesterol47.9% 11.7 pts above the national average of 36.2%
Housing insecurity10.7% 3.1 pts below the national average of 13.8%
Independent living disability9.9% 1.5 pts above the national average of 8.4%
Lacks transport7.3% 1.9 pts below the national average of 9.2%
Loneliness30.8% 3.6 pts below the national average of 34.4%
Mammography use79.9% 4 pts above the national average of 75.9%
Poor mental health (14+ days)15.2% 1.6 pts below the national average of 16.8%
Mobility disability21.6% 7.6 pts above the national average of 14%
Poor physical health (14+ days)17.9% 4.4 pts above the national average of 13.5%
Self-care disability5.5% 1.5 pts above the national average of 4%
Utility shut-off threat6.9% 1.9 pts below the national average of 8.8%
Sleeps under 7 hours36.4% same as the national average of 36.4%
Stroke5.9% 2.5 pts above the national average of 3.4%
All natural teeth lost11.3% 1.7 pts below the national average of 13%
Vision disability6.3% 0.7 pts above the national average of 5.6%
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Business and employment

Census ZIP Code Business Patterns 2022

Business establishments9
People employed66
Annual payroll$5,676,000
Natural hazard risk

FEMA National Risk Index, estimated for this ZIP code from census tract data — the NRI is not published per ZIP.

Overall riskHigher than 79.5% of US census tracts
FEMA ratingRelatively Moderate
Expected annual loss72.3 out of 100
Community resilience86.7 out of 100

By hazard

Score is out of 100 and is the area-weighted average across the census tracts this ZIP code covers. The rating beside it is the highest any one of those tracts carries.

Coastal flooding99.7Very High at its worst in this ZIP code
Wildfire96.9Relatively High at its worst in this ZIP code
Hurricane88.8Relatively Moderate at its worst in this ZIP code
Drought87.5Relatively Low at its worst in this ZIP code
Strong wind61.8Relatively Moderate at its worst in this ZIP code
Cold wave57.8Relatively Moderate at its worst in this ZIP code
Ice storm52.4Relatively Low at its worst in this ZIP code
Winter weather51Relatively Moderate at its worst in this ZIP code
Hail45.5Relatively Low at its worst in this ZIP code
Landslide34.1Very Low at its worst in this ZIP code
Earthquake29.3Very Low at its worst in this ZIP code
Lightning29.1Relatively Low at its worst in this ZIP code
Tornado25.2Very Low at its worst in this ZIP code
Heat wave17.4Relatively Low at its worst in this ZIP code
River flooding8.3Very Low at its worst in this ZIP code
Compared with Maryland and the United States

State and national columns are figures for those areas, not for this ZIP code. American Community Survey 2019–2023 five-year estimates

This ZIPMarylandUnited States
Median household income$51,500$101,652$78,538
Income per person$30,218$51,689$43,289
Poverty rate15.4%9.3%12.4%
Median home value$151,700$397,700$303,400
Median gross rent$1,356$1,662$1,348
Homeownership89.8%67.5%65%
Bachelor's degree or higher8.4%42.7%35%
Unemployment rate1.9%4.9%5.2%
Works from home8%17.2%13.5%
Born outside the US6%16.3%13.9%
Median age56.539.338.7
Climate

NOAA US Climate Normals 1991-2020, from the nearest weather station with a full year of records. The station and its distance are named above, because a station forty kilometres away describes somewhere else.

Weather stationVIENNA, MD US38.8 km away

Average high and low by month

January47.8°F / 27.7°F
February50.1°F / 28.5°F
March58.3°F / 35.5°F
April69.3°F / 44.1°F
May77.7°F / 54°F
June85.5°F / 63.1°F
July90.1°F / 68.7°F
August88.1°F / 66.6°F
September81.9°F / 60.5°F
October71.7°F / 48.6°F
November60.6°F / 38.5°F
December51.3°F / 31.2°F
Access to food

USDA Food Access Research Atlas, estimated for this ZIP code from census tract data. Each figure is the share of the ZIP code's land area that falls in a tract carrying that flag.

Low income and far from a supermarket100% of this ZIP code's area
Far from a supermarketNone of this ZIP code
No vehicle and far from a supermarket100% of this ZIP code's area
School districts

NCES Geographic Relationship File 2025, which states the association between each district and each ZIP code tabulation area directly. Elementary and secondary districts can cover the same ground, so shares need not total 100%.

Somerset County Public Schools100% of this ZIP code's land area
Community and walkability

CDC/ATSDR Social Vulnerability Index 2022 and the EPA National Walkability Index, both estimated for this ZIP code from census tract data. Vulnerability figures are national percentile ranks, not measurements.

Overall social vulnerability32more vulnerable than 32% of US census tracts
Socioeconomic status56more vulnerable than 56% of US census tracts
Household characteristics29more vulnerable than 29% of US census tracts
Racial and ethnic minority status19more vulnerable than 19% of US census tracts
Housing type and transport19more vulnerable than 19% of US census tracts
Walkability3.7 out of 20Least walkable
Nearby ZIP codes

The closest ZIP codes by centre point, which is not the same as sharing a border.

21890 Westover, MD8.6 km away
21840 Nanticoke, MD13.3 km away
21627 Crocheron, MD13.4 km away
21867 Upper Fairmount, MD14.9 km away
21672 Toddville, MD16.4 km away
21814 Bivalve, MD16.6 km away
21865 Tyaskin, MD17 km away
21836 Manokin, MD17.5 km away
Location, counties and time zone

County shares from Census 2020 ZCTA relationship files. Time zone from the USDOT National Transportation Atlas, which renders the boundaries written into 49 CFR Part 71.

Somerset County100% of this ZIP code's land area
Time zoneEastern (UTC-05:00 standard)
Daylight saving timeObserved
Land area14.74 sq mi
Water area5.07 sq mi
Population density50 people per sq mi
Latitude, longitude38.1533, -75.9496

Figures are published for this ZIP code or its Census tabulation area unless a section says otherwise. Estimates whose margin of error made them unreliable are omitted rather than shown. Sources: US Census Bureau, CDC, IRS.

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