Postal Codes

20634 ZIP Code

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ZIP code 20634 covers Great Mills, Maryland, with a population of about 6,976 and a median household income of $117,431.

Population
6,976998 per square mile
Median age
32.36.4 points below the US average
Median household income
$117,4311.2× the Maryland median
Poverty rate
4.3%8.1 points below the US average
Typical home value
$372,236up 16.4% in five years
Median rent
$1,689about the Maryland median
Degree or higher
40.6%5.6 points above the US average
Homeownership
68.3%3.3 points above the US average
Time zone
Eastern UTC-05:00observes daylight saving time
Businesses
50

Where 20634 is

Great Mills, 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

Population6,976
Median age32.3
Family households65.4%
Born outside the US5.9%
Speaks a language other than English at home4.6%
White (non-Hispanic)56.7%
Black (non-Hispanic)30.6%
Asian (non-Hispanic)2.5%
Hispanic or Latino4.7%
Veterans20.4%
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$117,431
Income per person$59,876
Poverty rate4.3%
Households on SNAP or cash assistance10.3%

Household income distribution

Under $10k0.6%
$10–15k2.0%
$15–20k0.6%
$20–25k1.6%
$25–30k2.9%
$30–35k3.3%
$35–40k0.0%
$40–45k0.6%
$45–50k2.0%
$50–60k2.9%
$60–75k8.6%
$75–100k19.8%
$100–125k6.0%
$125–150k13.4%
$150–200k19.6%
$200k or more16.2%

Income as declared to the IRS

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

Tax returns filed3,560
Mean adjusted gross income$80,974
Returns declaring $200,000 or more6.2%
Returns, under $25k21.3%
Returns, $25k–$50k20.2%
Returns, $50k–$75k14.9%
Returns, $75k–$100k12.1%
Returns, $100k–$200k25.3%
Returns, $200k or more6.2%
Housing

American Community Survey 2019–2023 five-year estimates

Median home value$334,800
Median gross rent$1,689
Rent as a share of household income26.8%
Owner-occupied68.3%
Vacant homes11.6%
Median year built1995

What the homes are

Detached house66.4%
Attached house17.9%
2 to 4 units3.1%
5 to 19 units11%
20 or more units1.6%
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$372,236as of 2026-07
Typical home value, 1 yearup 1.6%
Typical home value, 5 yearsup 16.4%
Typical home value, 10 yearsup 56.1%
Typical home value since 2000
200020132026$372,236$149,040

$149,040 in 2000 to $372,236 in 2026.

Work, commuting and education

American Community Survey 2019–2023 five-year estimates

Unemployment rate1.3%
Bachelor's degree or higher40.6%
High school diploma or higher97.5%
Works from home14.9%
Drives to work alone75.4%
Takes public transport0.8%
Commutes 45 minutes or more16.2%
Health

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

Obesity39.2% 5.8 pts above the national average of 33.4%
Diagnosed diabetes11% 1 pts below the national average of 12%
Currently smokes13.1% same as the national average of 13.2%
High blood pressure33% 1.1 pts below the national average of 34.1%
Fair or poor general health17.1% 3.2 pts below the national average of 20.3%
No health insurance (18–64)7.9% 3.4 pts below the national average of 11.3%
Depression21% 0.9 pts below the national average of 21.9%
No leisure-time physical activity22.8% 2.6 pts below the national average of 25.4%
Arthritis23.9% 1.2 pts below the national average of 25.1%
Binge drinking17.6% 1.6 pts above the national average of 16%
Taking blood pressure medication73% 1.7 pts below the national average of 74.7%
Cancer (non-skin)6% 1.7 pts below the national average of 7.7%
Current asthma11% 0.6 pts above the national average of 10.4%
Coronary heart disease4.5% 1.7 pts below the national average of 6.2%
Routine check-up in past year76.4% same as the national average of 76.7%
Cholesterol screening87.8% 1.9 pts above the national average of 85.9%
Cognitive disability13.5% 1.3 pts below the national average of 14.8%
Colorectal screening66.7% 2.4 pts above the national average of 64.3%
COPD5.1% 1.5 pts below the national average of 6.6%
Visited a dentist63.2% 1.9 pts above the national average of 61.3%
Any disability24.9% 5.8 pts below the national average of 30.7%
Lacks emotional support25.6% 0.8 pts above the national average of 24.8%
Food insecurity14.5% 2.6 pts below the national average of 17.1%
Received food stamps12% 2.3 pts below the national average of 14.3%
Hearing disability4.5% 2.2 pts below the national average of 6.7%
High cholesterol34.3% 1.9 pts below the national average of 36.2%
Housing insecurity13.9% same as the national average of 13.8%
Independent living disability6.7% 1.7 pts below the national average of 8.4%
Lacks transport8% 1.2 pts below the national average of 9.2%
Loneliness37.3% 2.9 pts above the national average of 34.4%
Mammography use77.2% 1.3 pts above the national average of 75.9%
Poor mental health (14+ days)17.3% 0.5 pts above the national average of 16.8%
Mobility disability10.4% 3.6 pts below the national average of 14%
Poor physical health (14+ days)11.5% 2 pts below the national average of 13.5%
Self-care disability3.1% 0.9 pts below the national average of 4%
Utility shut-off threat8.8% same as the national average of 8.8%
Sleeps under 7 hours41.2% 4.8 pts above the national average of 36.4%
Stroke2.6% 0.8 pts below the national average of 3.4%
All natural teeth lost10% 3 pts below the national average of 13%
Vision disability4% 1.6 pts below the national average of 5.6%
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Business and employment

Census ZIP Code Business Patterns 2022

Business establishments50
People employed345
Annual payroll$17,324,000
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 8.5% of US census tracts
FEMA ratingVery Low
Expected annual loss18.3 out of 100
Community resilience89 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.

Drought86.1Relatively Low at its worst in this ZIP code
Hurricane81Relatively Moderate at its worst in this ZIP code
Wildfire71.9Relatively Low at its worst in this ZIP code
Strong wind59.9Relatively Moderate at its worst in this ZIP code
Winter weather56.1Relatively Moderate at its worst in this ZIP code
Coastal flooding50.7Relatively Low at its worst in this ZIP code
Lightning49.7Relatively Moderate at its worst in this ZIP code
Landslide47.4Very Low at its worst in this ZIP code
Heat wave43.6Relatively Moderate at its worst in this ZIP code
Ice storm43.3Relatively Low at its worst in this ZIP code
Hail41.1Relatively Low at its worst in this ZIP code
Tornado36.5Relatively Low at its worst in this ZIP code
Earthquake31.5Very Low at its worst in this ZIP code
Cold wave28.5Relatively Low at its worst in this ZIP code
River flooding6.2Very 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$117,431$101,652$78,538
Income per person$59,876$51,689$43,289
Poverty rate4.3%9.3%12.4%
Median home value$334,800$397,700$303,400
Median gross rent$1,689$1,662$1,348
Homeownership68.3%67.5%65%
Bachelor's degree or higher40.6%42.7%35%
Unemployment rate1.3%4.9%5.2%
Works from home14.9%17.2%13.5%
Born outside the US5.9%16.3%13.9%
Median age32.339.338.7
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 stationSOLOMONS, MD US6.9 km away

Average high and low by month

January45.3°F / 30.1°F
February47.6°F / 30.8°F
March54.9°F / 37.6°F
April65.4°F / 47.4°F
May74.2°F / 57.9°F
June83.8°F / 67.6°F
July87.9°F / 72.7°F
August86.3°F / 71°F
September79.9°F / 65°F
October68.7°F / 53.4°F
November58.6°F / 43°F
December50.1°F / 34.5°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 supermarketNone of this ZIP code
Far from a supermarket42% of this ZIP code's area
No vehicle and far from a supermarket13% 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%.

St. Marys 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 vulnerability23more vulnerable than 23% of US census tracts
Socioeconomic status14more vulnerable than 14% of US census tracts
Household characteristics25more vulnerable than 25% of US census tracts
Racial and ethnic minority status53more vulnerable than 53% of US census tracts
Housing type and transport46more vulnerable than 46% of US census tracts
Walkability6.5 out of 20Below average
Nearby ZIP codes

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

20653 Lexington Park, MD4.2 km away
20619 California, MD4.8 km away
20620 Callaway, MD5 km away
20670 Patuxent River, MD5.2 km away
20667 Park Hall, MD7.2 km away
20688 Solomons, MD7.4 km away
20629 Dowell, MD8.5 km away
20692 Valley Lee, MD8.7 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.

St. Mary's County100% of this ZIP code's land area
Time zoneEastern (UTC-05:00 standard)
Daylight saving timeObserved
Land area6.99 sq mi
Water area0.07 sq mi
Population density998 people per sq mi
Latitude, longitude38.2674, -76.4954

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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