21821 ZIP Code — Deal Island, MD

Somerset County, Maryland

ZIP code 21821 is located in Deal Island, Maryland, within Somerset County. It covers approximately 14.74 square miles and serves a population of 765 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 410/667.

About ZIP code 21821

The housing stock consists of predominantly single-family detached homes. Most homes were built in the pre-1940, giving the area an established character. Median home value is $176,600. Owner-occupancy is high at 92%, well above the national average.

Median household income is $42,250. 58% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is sales and office, with retail trade as the leading industry. The average commute of 30 minutes is near the national average.

College attainment at 12% is below the national average, consistent with a trades and production-oriented local economy.

Health indicators show elevated rates of smoking (20%) compared to national benchmarks.

Notable community characteristics include disability rates above the national average at 27%.

Overall, ZIP code 21821 reflects a community defined by a trades-oriented workforce, high homeownership, and a significant Social Security-dependent population.

765

population

14.74

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

21821 ZIP code map

Cities in ZIP code 21821

Below are the cities the US Postal Service accepts for ZIP code 21821. Using any city not on this list may result in mail delivery delays.

City	Status
Deal Island	Acceptable
Deal Island	Preferred

Nearby ZIP codes

21890 Westover (8.6 mi) 21840 Nanticoke (9.5 mi) 21824 Ewell (10 mi) 21814 Bivalve (11.8 mi) 21865 Tyaskin (12.7 mi) 21817 Crisfield (13.1 mi) 21871 Westover (13.7 mi) 21626 Crapo (13.8 mi) 21853 Princess Anne (15.1 mi) 21634 Fishing Creek (15.3 mi) 21838 Marion Station (15.6 mi) 21856 Quantico (15.9 mi)

Demographics updated 05/2026

Population
Total population	765
Population density	52 / sq mi
State FIPS	24
County FIPS	039

Geography
Land area	14.74 sq mi
Water area	5.07 sq mi
Latitude	38.1379
Longitude	-75.9741
Timezone	Eastern (ET)
Area code	410/667

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	57.9%	52.7%	28.2%
$50k – $100k	30.3%	31.5%	28.2%
$100k – $200k	8.7%	14.6%	30.1%
Over $200k	3.1%	1.2%	13.4%

Demographics & statistics

765

Population

People per sq mi

45.3

Median age

$42,250

Median household income

$28,345

Per capita income

$176,600

Median home value

Median monthly rent

92.3%

Home ownership

11.1%

Poverty rate

5.3%

Unemployment

733

Housing units

11.6%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

20–24

25–34

35–44

109

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	66	8.6%
18 and over	699	91.4%
65 and over	234	30.6%
Median age	45.3 years

Race & ethnicity

White 85.3%

Two or more races 5.5%

Hispanic or Latino 5%

Black or African American 4.2%

Group	Count	%
White	687	85.3%
Two or more races	44	5.5%
Hispanic or Latino	40	5%
Black or African American	34	4.2%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	57.9%	52.7%	28.2%
$50k – $100k	30.3%	31.5%	28.2%
$100k – $200k	8.7%	14.6%	30.1%
Over $200k	3.1%	1.2%	13.4%

Under $10k 6.3%

$10k–$15k 6.8%

$15k–$25k 14.2%

$25k–$35k 15.9%

$35k–$50k 11.0%

$50k–$75k 21.9%

$75k–$100k 10.7%

$100k–$150k 10.4%

$150k–$200k 2.7%

Range	% of households
Under $10k	6.3%
$10k–$15k	6.8%
$15k–$25k	14.2%
$25k–$35k	15.9%
$35k–$50k	11.0%
$50k–$75k	21.9%
$75k–$100k	10.7%
$100k–$150k	10.4%
$150k–$200k	2.7%
Median income	$42,250

Housing

Home values

Under $50k 3.3%

$50k–$100k 13.4%

$100k–$150k 24.0%

$150k–$200k 24.9%

$200k–$300k 14.2%

$300k–$500k 18.1%

$500k–$1M 2.1%

Housing overview

Metric	Value
Median home value	$176,600
Median rent / month	$0
Owner occupied	92.3%
Renter occupied	7.7%
Vacant	52.0%
Single-family detached	88.7%
Large apartment buildings	0.0%
Mobile homes	8.7%
Median rooms	5.8
Avg household size (owned)	2.12

Year built

Era	%
2020 or later	0.0%
2010–2019	2.9%
2000–2009	12.7%
1990–1999	5.3%
1980–1989	13.9%
1970–1979	13.7%
1960–1969	11.4%
1950–1959	6.2%
1940–1949	1.3%
1939 or earlier	32.6%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	0.0%
2 bedrooms	39.9%
3 bedrooms	49.1%
4 bedrooms	9.1%
5+ bedrooms	1.8%

Vehicles per household

Vehicles	% of households
No vehicle	0.0%
1 vehicle	51.2%
2 vehicles	27.1%
3 or more	21.6%

Heating fuel

Fuel type	%
Utility gas	4.9%
Electricity	47.9%
Propane / LP gas	18.6%
Fuel oil	22.5%
Wood	3.6%
Solar	1.1%

Households & families

Household type	Count	%
Married-couple family	113	31.0%
Cohabiting couple	8	2.2%
Male householder, no spouse	39	10.7%
Female householder, no spouse	205	56.2%
Households with children under 18	64	17.5%
Households with seniors (65+)	208	57.0%
Average household size	2.10

Marital status

Status	Male	Female
Never married	25.1%	14.8%
Married	55.3%	45.0%
Separated	8.1%	2.1%
Widowed	7.5%	28.9%
Divorced	4.1%	9.2%

Education

Less than 9th grade 2.7%

Some HS, no diploma 11.0%

HS graduate 35.2%

Some college, no degree 32.7%

Associate's degree 6.8%

Bachelor's degree 10.1%

Graduate / professional 1.5%

Metric	%
HS diploma or higher	86.3%
Bachelor's or higher	11.6%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	0	0.0%
Kindergarten	5	6.3%
Elementary school	23	28.8%
High school	29	36.3%
College / grad school	23	28.8%

Employment

Industry of employment

Retail trade 35.2%

Education & healthcare 18.2%

Construction 11.2%

Agriculture & mining 7.8%

Professional & management 7.3%

Wholesale trade 6.4%

Public administration 5.3%

Finance & real estate 3.4%

Manufacturing 2.5%

Other services 1.7%

Arts, food & hospitality 1.1%

Occupation

Category	%
Management, business & arts	23.7%
Service	12.3%
Sales & office	38.8%
Natural resources & construction	16.5%
Production & transportation	8.7%

Employment type

Type	%
Private sector	67.0%
Government	22.1%
Self-employed	10.9%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	44.5%
Carpool	45.6%
Public transit	0.0%
Walk	2.8%
Work from home	5.4%
Other means	1.7%
Avg commute (minutes)	30.3

Poverty

All people 11.1%

Under 18 years 14.3%

18 and over 10.9%

Married-couple families 0.0%

Female-led households 18.3%

Income support

Source	% of households
Social Security	58.1%
Retirement income	40.8%
Supplemental Security	6.8%
Cash public assistance	10.1%
Food stamps / SNAP	15.3%

Health indicators

Condition	%
Obesity	35.6%
High blood pressure	45.9%
High cholesterol	42.4%
Diabetes	14.4%
Heart disease	9.2%
Stroke	4.5%
Asthma	10.4%
Arthritis	35.1%
Kidney disease	4.0%
Pulmonary disease	10.0%
Cancer	8.8%

Behavior / access	%
Smoking	20.1%
Binge drinking	12.8%
No physical activity	30.0%
Less than 7 hrs sleep	32.9%
Depression	20.4%
Fair or poor health	17.8%
Poor mental health	14.3%
Poor physical health	12.2%
No health insurance	11.8%
Visited doctor (checkup)	79.6%
Visited dentist	55.9%
Cholesterol screening	92.4%
Teeth loss	15.8%

Veterans & disability

Veterans	Count	%
Civilian veterans	54	7.7%

Disability	%
Any disability	27.2%
Under 18	18.2%
18–64 years	15.3%
65 and over	53.4%

Health insurance coverage

Type	%
Private insurance	62.9%
Public insurance	58.3%
No insurance	3.9%
Uninsured under 19	7.6%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	756	98.8%
Spanish	4	0.5%
Other Indo-European	0	0.0%
Asian & Pacific Islander	0	0.0%
Other languages	4	0.5%

Place of birth & citizenship

Origin	Count	%
Native born (US)	714	93.3%
Born in same state	714	93.3%
Born in different state	540	70.6%
Foreign born	0	0.0%
Naturalized citizen	51	6.7%
Not a US citizen	23	45.1%

Ancestry

Ancestry	Count	%
Arab	214	28%
French	201	26.3%

Ancestry	Count	%
Italian	24	3.1%

Technology access

Metric	% of households
Computer access	47.7%
Internet access	76.7%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 21821

What city is ZIP code 21821 in?

ZIP code 21821 is primarily assigned to Deal Island, Maryland.

What county is ZIP code 21821 in?

ZIP code 21821 falls within Somerset County, Maryland.

Does ZIP code 21821 have a large retiree population?

58% of households in ZIP code 21821 receive Social Security income, suggesting a significant retiree or disability population.

Does ZIP code 21821 have an older population?

31% of residents in ZIP code 21821 are 65 or older, above the national average of ~17%.

Is ZIP code 21821 mostly owner-occupied?

92% of occupied units in ZIP code 21821 are owner-occupied, well above the national average.

How educated is the population of ZIP code 21821?

12% of residents hold a bachelor's degree or higher — below the national average of ~33%, consistent with a trades-oriented local economy.

What timezone is ZIP code 21821 in?

ZIP code 21821 observes the EST timezone.