Postal Codes

21104 ZIP Code

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ZIP code 21104 covers Marriottsville, Maryland, with a population of about 5,786 and a median household income of $199,803.

Population
5,786339 per square mile
Median age
467.3 points above the US average
Median household income
$199,8032.0× the Maryland median
Poverty rate
2.5%9.9 points below the US average
Typical home value
$733,393up 16.4% in five years
Degree or higher
63.3%28.3 points above the US average
Homeownership
96.9%31.9 points above the US average
Time zone
Eastern UTC-05:00observes daylight saving time
Businesses
147

Where 21104 is

Marriottsville, 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

Population5,786
Median age46
Family households80.6%
Born outside the US14.6%
Speaks a language other than English at home17.8%
White (non-Hispanic)74.9%
Black (non-Hispanic)4.2%
Asian (non-Hispanic)10.3%
Hispanic or Latino1.8%
Veterans4.7%
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$199,803
Income per person$74,924
Poverty rate2.5%
Households on SNAP or cash assistance1.3%

Household income distribution

Under $10k0.5%
$10–15k0.0%
$15–20k0.5%
$20–25k1.3%
$25–30k0.9%
$30–35k0.9%
$35–40k1.3%
$40–45k0.6%
$45–50k0.5%
$50–60k3.9%
$60–75k3.7%
$75–100k7.1%
$100–125k4.5%
$125–150k11.7%
$150–200k12.6%
$200k or more49.9%

Income as declared to the IRS

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

Tax returns filed2,960
Mean adjusted gross income$180,880
Returns declaring $200,000 or more26.7%
Returns, under $25k18.2%
Returns, $25k–$50k9.8%
Returns, $50k–$75k9.1%
Returns, $75k–$100k8.4%
Returns, $100k–$200k27.7%
Returns, $200k or more26.7%
Housing

American Community Survey 2019–2023 five-year estimates

Median home value$659,700
Rent as a share of household income46.3%
Owner-occupied96.9%
Vacant homes2.7%
Median year built1994

What the homes are

Detached house87.8%
Attached house9.5%
5 to 19 units2.7%
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$733,393as of 2026-07
Typical home value, 1 yearup 0.6%
Typical home value, 5 yearsup 16.4%
Typical home value, 10 yearsup 44.3%
Typical home value since 2000
200020132026$733,393$264,350

$264,350 in 2000 to $733,393 in 2026.

Work, commuting and education

American Community Survey 2019–2023 five-year estimates

Unemployment rate2.5%
Bachelor's degree or higher63.3%
High school diploma or higher98.3%
Works from home19.6%
Drives to work alone75.6%
Takes public transport0.2%
Commutes 45 minutes or more22.1%
Health

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

Obesity31.1% 2.3 pts below the national average of 33.4%
Diagnosed diabetes10.7% 1.3 pts below the national average of 12%
Currently smokes7.5% 5.7 pts below the national average of 13.2%
High blood pressure36.3% 2.2 pts above the national average of 34.1%
Fair or poor general health11.9% 8.4 pts below the national average of 20.3%
No health insurance (18–64)4.3% 7 pts below the national average of 11.3%
Depression19.6% 2.3 pts below the national average of 21.9%
No leisure-time physical activity17.1% 8.3 pts below the national average of 25.4%
Arthritis29.1% 4 pts above the national average of 25.1%
Binge drinking14.5% 1.5 pts below the national average of 16%
Taking blood pressure medication79.3% 4.6 pts above the national average of 74.7%
Cancer (non-skin)10.8% 3.1 pts above the national average of 7.7%
Current asthma9.3% 1.1 pts below the national average of 10.4%
Coronary heart disease5.9% same as the national average of 6.2%
Routine check-up in past year80.6% 3.9 pts above the national average of 76.7%
Cholesterol screening92.2% 6.3 pts above the national average of 85.9%
Cognitive disability8.8% 6 pts below the national average of 14.8%
Colorectal screening73.1% 8.8 pts above the national average of 64.3%
COPD5% 1.6 pts below the national average of 6.6%
Visited a dentist73.6% 12.3 pts above the national average of 61.3%
Any disability21.7% 9 pts below the national average of 30.7%
Lacks emotional support18.1% 6.7 pts below the national average of 24.8%
Food insecurity6.3% 10.8 pts below the national average of 17.1%
Received food stamps4.2% 10.1 pts below the national average of 14.3%
Hearing disability6.1% 0.6 pts below the national average of 6.7%
High cholesterol42.4% 6.2 pts above the national average of 36.2%
Housing insecurity5.8% 8 pts below the national average of 13.8%
Independent living disability4.7% 3.7 pts below the national average of 8.4%
Lacks transport4% 5.2 pts below the national average of 9.2%
Loneliness28.3% 6.1 pts below the national average of 34.4%
Mammography use83.4% 7.5 pts above the national average of 75.9%
Poor mental health (14+ days)12.1% 4.7 pts below the national average of 16.8%
Mobility disability9.8% 4.2 pts below the national average of 14%
Poor physical health (14+ days)10.1% 3.4 pts below the national average of 13.5%
Self-care disability2.3% 1.7 pts below the national average of 4%
Utility shut-off threat3.7% 5.1 pts below the national average of 8.8%
Sleeps under 7 hours32.9% 3.5 pts below the national average of 36.4%
Stroke2.8% 0.6 pts below the national average of 3.4%
All natural teeth lost5.2% 7.8 pts below the national average of 13%
Vision disability2.9% 2.7 pts below the national average of 5.6%
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Business and employment

Census ZIP Code Business Patterns 2022

Business establishments147
People employed1,260
Annual payroll$68,845,000
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 12% of US census tracts
FEMA ratingVery Low to Relatively Low across the 6 census tracts this ZIP code covers
Expected annual loss24.8 out of 100
Community resilience82.8 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.

Drought86.2Relatively Moderate at its worst in this ZIP code
Landslide80.4Relatively Low at its worst in this ZIP code
Winter weather78.7Relatively High at its worst in this ZIP code
Strong wind71.4Relatively High at its worst in this ZIP code
Hurricane65.1Relatively Low at its worst in this ZIP code
Lightning58.3Relatively Moderate at its worst in this ZIP code
Heat wave56.3Relatively Moderate at its worst in this ZIP code
Hail54.5Relatively Moderate at its worst in this ZIP code
Wildfire42.5Very Low at its worst in this ZIP code
Earthquake38Relatively Low at its worst in this ZIP code
Cold wave30.9Relatively Low at its worst in this ZIP code
Tornado29.8Relatively Low at its worst in this ZIP code
Ice storm24.9Relatively Low at its worst in this ZIP code
River flooding20Relatively Moderate at its worst in this ZIP code
Avalanche3Very 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$199,803$101,652$78,538
Income per person$74,924$51,689$43,289
Poverty rate2.5%9.3%12.4%
Median home value$659,700$397,700$303,400
Median gross rent$1,662$1,348
Homeownership96.9%67.5%65%
Bachelor's degree or higher63.3%42.7%35%
Unemployment rate2.5%4.9%5.2%
Works from home19.6%17.2%13.5%
Born outside the US14.6%16.3%13.9%
Median age4639.338.7
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 stationCYLBURN, MD US22.4 km away

Average high and low by month

January42.4°F / 26.6°F
February46.3°F / 28.3°F
March53.8°F / 34.2°F
April65.5°F / 44.9°F
May73.2°F / 54.5°F
June82°F / 63.9°F
July86.5°F / 69.3°F
August83.9°F / 67°F
September76.8°F / 59.8°F
October66.3°F / 48.5°F
November56.4°F / 38.7°F
December46.4°F / 31.5°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 supermarket66% of this ZIP code's area
No vehicle and far from a supermarketNone of this ZIP code
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%.

This ZIP code is served by 3 school districts, so the address decides which one, not the ZIP code.

Howard County Public Schools53.4% of this ZIP code's land area
Carroll County Public Schools31.9% of this ZIP code's land area
Baltimore County Public Schools14.7% 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 vulnerability17more vulnerable than 17% of US census tracts
Socioeconomic status12more vulnerable than 12% of US census tracts
Household characteristics31more vulnerable than 31% of US census tracts
Racial and ethnic minority status50more vulnerable than 50% of US census tracts
Housing type and transport25more vulnerable than 25% of US census tracts
Walkability6.4 out of 20Below average
Nearby ZIP codes

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

21163 Woodstock, MD6.1 km away
21794 West Friendship, MD6.4 km away
21723 Cooksville, MD8 km away
21042 Ellicott City, MD8.2 km away
21738 Glenwood, MD10.6 km away
21133 Randallstown, MD10.7 km away
21244 Windsor Mill, MD11 km away
21041 Ellicott City, MD11.2 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.

Howard County53.4% of this ZIP code's land area
Carroll County31.9% of this ZIP code's land area
Baltimore County14.7% of this ZIP code's land area
Time zoneEastern (UTC-05:00 standard)
Daylight saving timeObserved
Land area17.05 sq mi
Water area0.81 sq mi
Population density339 people per sq mi
Latitude, longitude39.3342, -76.9132

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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