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Maryland ZIP Codes
Caroline County
Henderson, MD
21640
21640 ZIP Code — Henderson, MD
Caroline County, Maryland
ZIP code 21640 is located in
Henderson ,
Maryland ,
within Caroline County .
It covers approximately 25.66 square miles and serves a population of
1,374 residents.
This is a standard ZIP code in the Eastern (ET) timezone,
served by area code 410/667 .
About ZIP code 21640
The housing stock consists of a higher-than-average concentration of mobile homes. Most homes were built in the 1990s, giving the area an established character. Median home value is $261,100. Owner-occupancy is high at 96%, well above the national average.
Median household income is $77,721. The poverty rate of 5% is below the national average. SNAP benefit usage at 18% of households reflects economic stress in the area. 50% of households receive Social Security income, suggesting a notable retiree or disability population.
The dominant occupation class is service, with agriculture and mining as the leading industry. The average commute of 31 minutes is near the national average.
College attainment at 11% is below the national average, consistent with a trades and production-oriented local economy.
Health indicators show elevated rates of smoking (23%) compared to national benchmarks. 20% of residents lack health insurance, above the national average.
Notable community characteristics include Spanish spoken in 26% of households.
Overall, ZIP code 21640 reflects a community defined by a trades-oriented workforce, high homeownership, a significant Social Security-dependent population, and elevated reliance on food assistance.
21640 ZIP code map
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Cities in ZIP code 21640
Below are the cities the US Postal Service accepts for ZIP code 21640. Using any city not on this list may result in mail delivery delays.
Nearby ZIP codes
Demographics
updated 05/2026
Population
Total population
1,374
Population density
54 / sq mi
State FIPS
24
County FIPS
011
Geography
Land area
25.66 sq mi
Water area
0.08 sq mi
Latitude
39.0693
Longitude
-75.8160
Timezone
Eastern (ET)
Area code
410/667
Economics
updated 05/2026
Household income
Income range
This ZIP
County avg
State avg
Under $50k
32.6%
40.1%
28.2%
$50k – $100k
43.7%
34.3%
28.2%
$100k – $200k
23.7%
21.3%
30.1%
Over $200k
0.0%
4.3%
13.4%
Demographics & statistics
$77,721
Median household income
$261,100
Median home value
$1,650
Median monthly rent
11.1%
Bachelor's or higher
Age distribution
Age summary
Group Count %
Under 18 335 24.4%
18 and over 1,039 75.6%
65 and over 370 26.9%
Median age 39.3 years
Race & ethnicity
American Indian / Alaska Native
1.4%
Group Count %
White 1,064 64.1%
Hispanic or Latino 286 17.2%
Other race 233 14%
Two or more races 53 3.2%
American Indian / Alaska Native 23 1.4%
Asian 1 0.1%
Household income
Income range
This ZIP
County avg
State avg
Under $50k
32.6%
40.1%
28.2%
$50k – $100k
43.7%
34.3%
28.2%
$100k – $200k
23.7%
21.3%
30.1%
Over $200k
0.0%
4.3%
13.4%
Range % of households
$10k–$15k 4.3%
$15k–$25k 13.8%
$25k–$35k 4.5%
$35k–$50k 7.5%
$50k–$75k 19.6%
$75k–$100k 27.1%
$100k–$150k 13.4%
$150k–$200k 9.8%
Median income $77,721
Housing
Housing overview
Metric Value
Median home value $261,100
Median rent / month $1,650
Owner occupied 95.7%
Renter occupied 4.3%
Vacant 4.7%
Single-family detached 64.1%
Large apartment buildings 0.0%
Mobile homes 35.3%
Median rooms 5.5
Avg household size (owned) 2.84
Year built
Era %
2020 or later 0.0%
2010–2019 3.3%
2000–2009 9.9%
1990–1999 29.7%
1980–1989 21.2%
1970–1979 17.7%
1960–1969 10.1%
1950–1959 1.0%
1940–1949 1.9%
1939 or earlier 5.2%
Bedrooms
Size % of units
No bedroom (studio) 0.0%
1 bedroom 1.2%
2 bedrooms 20.4%
3 bedrooms 75.1%
4 bedrooms 3.3%
5+ bedrooms 0.0%
Vehicles per household
Vehicles % of households
No vehicle 3.3%
1 vehicle 18.5%
2 vehicles 40.9%
3 or more 37.3%
Heating fuel
Fuel type %
Utility gas 2.9%
Electricity 59.1%
Propane / LP gas 19.1%
Fuel oil 11.8%
Wood 4.9%
Households & families
Household type Count %
Married-couple family 198 40.3%
Cohabiting couple 113 23.0%
Male householder, no spouse 64 13.0%
Female householder, no spouse 116 23.6%
Households with children under 18 170 34.6%
Households with seniors (65+) 242 49.3%
Average household size 2.80
Marital status
Status Male Female
Never married 42.2% 24.3%
Married 35.3% 38.1%
Separated 0.0% 5.5%
Widowed 3.8% 13.8%
Divorced 18.8% 18.2%
Education
Less than 9th grade
17.2%
Some college, no degree
6.9%
Graduate / professional
0.0%
Metric %
HS diploma or higher 75.9%
Bachelor's or higher 11.1%
School enrollment (ages 3–17)
Type Count %
Nursery / preschool 12 3.8%
Kindergarten 30 9.4%
Elementary school 145 45.5%
High school 108 33.9%
College / grad school 24 7.5%
Employment
Industry of employment
Agriculture & mining
18.2%
Education & healthcare
12.7%
Professional & management
9.4%
Arts, food & hospitality
9.4%
Public administration
6.6%
Transportation & utilities
6.0%
Finance & real estate
4.6%
Occupation
Category %
Management, business & arts 12.7%
Service 38.1%
Sales & office 20.7%
Natural resources & construction 16.1%
Production & transportation 12.4%
Employment type
Type %
Private sector 75.7%
Government 14.6%
Self-employed 9.8%
Unpaid family workers 0.0%
Commute
Method %
Drive alone 85.9%
Carpool 12.3%
Public transit 0.0%
Walk 1.8%
Work from home 0.0%
Other means 0.0%
Avg commute (minutes) 31.1
Poverty
Married-couple families
0.0%
Female-led households
0.0%
Income support
Source % of households
Social Security 49.5%
Retirement income 31.0%
Supplemental Security 2.9%
Cash public assistance 0.0%
Food stamps / SNAP 17.7%
Health indicators
Condition %
Obesity 38.8%
High blood pressure 35.6%
High cholesterol 33.5%
Diabetes 12.3%
Heart disease 6.8%
Stroke 3.6%
Asthma 11.3%
Arthritis 28.6%
Kidney disease 3.1%
Pulmonary disease 9.3%
Cancer 6.1%
Behavior / access %
Smoking 23.3%
Binge drinking 15.0%
No physical activity 29.7%
Less than 7 hrs sleep 35.6%
Depression 23.5%
Fair or poor health 18.7%
Poor mental health 17.9%
Poor physical health 12.3%
No health insurance 15.4%
Visited doctor (checkup) 76.5%
Visited dentist 54.2%
Cholesterol screening 88.0%
Teeth loss 18.6%
Veterans & disability
Veterans Count %
Civilian veterans 38 3.7%
Disability %
Any disability 16.2%
Under 18 5.4%
18–64 years 9.7%
65 and over 37.8%
Health insurance coverage
Type %
Private insurance 42.3%
Public insurance 51.0%
No insurance 20.4%
Uninsured under 19 2.7%
Language & origin
Language spoken at home (age 5+)
Language Count %
English only 1,311 95.4%
Spanish 339 25.9%
Other Indo-European 339 25.9%
Asian & Pacific Islander 0 0.0%
Other languages 0 0.0%
Place of birth & citizenship
Origin Count %
Native born (US) 1,154 84.0%
Born in same state 1,154 84.0%
Born in different state 856 62.3%
Foreign born 0 0.0%
Naturalized citizen 220 16.0%
Not a US citizen 21 9.5%
Ancestry
Ancestry Count %
French 138 10%
Arab 129 9.4%
Ancestry Count %
Italian 23 1.7%
Technology access
Metric % of households
Computer access 35.7%
Internet access 88.8%
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 21640
What city is ZIP code 21640 in?
ZIP code 21640 is primarily assigned to Henderson, Maryland.
What county is ZIP code 21640 in?
ZIP code 21640 falls within Caroline County, Maryland.
Is ZIP code 21640 mostly owner-occupied?
96% of occupied units in ZIP code 21640 are owner-occupied, well above the national average.
Does ZIP code 21640 have an older population?
27% of residents in ZIP code 21640 are 65 or older, above the national average of ~17%.
Is Spanish widely spoken in ZIP code 21640?
Approximately 26% of households in ZIP code 21640 speak Spanish as a primary language.
Does ZIP code 21640 have a large retiree population?
50% of households in ZIP code 21640 receive Social Security income, suggesting a significant retiree or disability population.
What timezone is ZIP code 21640 in?
ZIP code 21640 observes the EST timezone.
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