Postal Codes

21770 ZIP Code

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ZIP code 21770 covers Monrovia, Maryland, with a population of about 7,815 and a median household income of $184,464.

Population
7,815683 per square mile
Median age
41.22.5 points above the US average
Median household income
$184,4641.8× the Maryland median
Poverty rate
1.4%11 points below the US average
Typical home value
$669,202up 19.7% in five years
Degree or higher
54.5%19.5 points above the US average
Homeownership
98%33 points above the US average
Time zone
Eastern UTC-05:00observes daylight saving time
Businesses
144

Where 21770 is

Monrovia, 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

Population7,815
Median age41.2
Family households87.6%
Born outside the US13.8%
Speaks a language other than English at home12.9%
White (non-Hispanic)76%
Black (non-Hispanic)5%
Asian (non-Hispanic)12%
Hispanic or Latino3.9%
Veterans8%
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$184,464
Income per person$63,232
Poverty rate1.4%
Households on SNAP or cash assistance4.7%

Household income distribution

Under $10k1.2%
$10–15k0.0%
$15–20k0.3%
$20–25k0.0%
$25–30k1.1%
$30–35k0.6%
$35–40k0.9%
$40–45k0.0%
$45–50k0.0%
$50–60k3.8%
$60–75k1.1%
$75–100k6.1%
$100–125k4.8%
$125–150k11.1%
$150–200k23.5%
$200k or more45.4%

Income as declared to the IRS

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

Tax returns filed4,120
Mean adjusted gross income$131,994
Returns declaring $200,000 or more20.6%
Returns, under $25k17.2%
Returns, $25k–$50k10.9%
Returns, $50k–$75k10.7%
Returns, $75k–$100k9.0%
Returns, $100k–$200k31.6%
Returns, $200k or more20.6%
Housing

American Community Survey 2019–2023 five-year estimates

Median home value$599,700
Owner-occupied98%
Vacant homes2.2%
Median year built1988

What the homes are

Detached house97.1%
Attached house2.9%
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$669,202as of 2026-07
Typical home value, 1 yearup 0.5%
Typical home value, 5 yearsup 19.7%
Typical home value, 10 yearsup 55.1%
Typical home value since 2000
200020132026$669,202$236,706

$236,706 in 2000 to $669,202 in 2026.

Work, commuting and education

American Community Survey 2019–2023 five-year estimates

Unemployment rate2.2%
Bachelor's degree or higher54.5%
High school diploma or higher98.5%
Works from home25.7%
Drives to work alone64.6%
Takes public transport0%
Commutes 45 minutes or more38.9%
Health

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

Obesity32.9% 0.5 pts below the national average of 33.4%
Diagnosed diabetes9.6% 2.4 pts below the national average of 12%
Currently smokes8.2% 5 pts below the national average of 13.2%
High blood pressure32.6% 1.5 pts below the national average of 34.1%
Fair or poor general health12.6% 7.7 pts below the national average of 20.3%
No health insurance (18–64)6% 5.3 pts below the national average of 11.3%
Depression20.6% 1.3 pts below the national average of 21.9%
No leisure-time physical activity17.4% 8 pts below the national average of 25.4%
Arthritis25.3% same as the national average of 25.1%
Binge drinking15.9% same as the national average of 16%
Taking blood pressure medication75.9% 1.2 pts above the national average of 74.7%
Cancer (non-skin)9% 1.3 pts above the national average of 7.7%
Current asthma9.4% 1 pts below the national average of 10.4%
Coronary heart disease5% 1.2 pts below the national average of 6.2%
Routine check-up in past year79% 2.3 pts above the national average of 76.7%
Cholesterol screening90.9% 5 pts above the national average of 85.9%
Cognitive disability9.9% 4.9 pts below the national average of 14.8%
Colorectal screening71% 6.7 pts above the national average of 64.3%
COPD4.7% 1.9 pts below the national average of 6.6%
Visited a dentist72% 10.7 pts above the national average of 61.3%
Any disability20.5% 10.2 pts below the national average of 30.7%
Lacks emotional support21.4% 3.4 pts below the national average of 24.8%
Food insecurity7.9% 9.2 pts below the national average of 17.1%
Received food stamps5.4% 8.9 pts below the national average of 14.3%
Hearing disability5.3% 1.4 pts below the national average of 6.7%
High cholesterol39.5% 3.3 pts above the national average of 36.2%
Housing insecurity7.9% 5.9 pts below the national average of 13.8%
Independent living disability4.9% 3.5 pts below the national average of 8.4%
Lacks transport4.8% 4.4 pts below the national average of 9.2%
Loneliness30.6% 3.8 pts below the national average of 34.4%
Mammography use78.1% 2.2 pts above the national average of 75.9%
Poor mental health (14+ days)14.2% 2.6 pts below the national average of 16.8%
Mobility disability8.4% 5.6 pts below the national average of 14%
Poor physical health (14+ days)9.8% 3.7 pts below the national average of 13.5%
Self-care disability2.3% 1.7 pts below the national average of 4%
Utility shut-off threat5% 3.8 pts below the national average of 8.8%
Sleeps under 7 hours34.1% 2.3 pts below the national average of 36.4%
Stroke2.5% 0.9 pts below the national average of 3.4%
All natural teeth lost5.7% 7.3 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 establishments144
People employed1,515
Annual payroll$79,225,000
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 20% of US census tracts
FEMA ratingVery Low to Relatively Low across the 3 census tracts this ZIP code covers
Expected annual loss33.2 out of 100
Community resilience69.3 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.

Drought87.9Relatively Low at its worst in this ZIP code
Winter weather84.2Relatively High at its worst in this ZIP code
Landslide81.3Relatively Low at its worst in this ZIP code
Strong wind71.4Relatively Moderate at its worst in this ZIP code
Lightning69.8Relatively Moderate at its worst in this ZIP code
Hail68.3Relatively Low at its worst in this ZIP code
Hurricane67.2Relatively Low at its worst in this ZIP code
Heat wave61.7Relatively Moderate at its worst in this ZIP code
Tornado50.5Relatively Low at its worst in this ZIP code
Earthquake45Relatively Low at its worst in this ZIP code
Ice storm35.5Relatively Low at its worst in this ZIP code
Wildfire35.5Very Low at its worst in this ZIP code
River flooding33.5Relatively Low at its worst in this ZIP code
Cold wave25.3Relatively 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$184,464$101,652$78,538
Income per person$63,232$51,689$43,289
Poverty rate1.4%9.3%12.4%
Median home value$599,700$397,700$303,400
Median gross rent$1,662$1,348
Homeownership98%67.5%65%
Bachelor's degree or higher54.5%42.7%35%
Unemployment rate2.2%4.9%5.2%
Works from home25.7%17.2%13.5%
Born outside the US13.8%16.3%13.9%
Median age41.239.338.7
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 stationDAMASCUS 3 SSW, MD US9.7 km away
Rain in a year48 in
Snow in a year31 in

Average high and low by month

January39.1°F / 24.5°F3.41 in rain, 9.4 in snow
February42.6°F / 26.1°F2.98 in rain, 11.1 in snow
March51.6°F / 33.1°F4.04 in rain, 4.8 in snow
April63.9°F / 42.9°F3.62 in rain, 0.2 in snow
May72.5°F / 52.8°F4.35 in rain
June80.2°F / 61.5°F4.67 in rain
July84.3°F / 66°F4.49 in rain
August82.6°F / 64.6°F4.18 in rain
September75.7°F / 57.6°F4.76 in rain
October64.5°F / 46.5°F4.01 in rain
November53.3°F / 36.4°F3.49 in rain, 0.8 in snow
December43.5°F / 29.5°F3.89 in rain, 5.1 in snow
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 supermarket100% 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%.

Frederick 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 vulnerability3more vulnerable than 3% of US census tracts
Socioeconomic status2more vulnerable than 2% of US census tracts
Household characteristics23more vulnerable than 23% of US census tracts
Racial and ethnic minority status41more vulnerable than 41% of US census tracts
Housing type and transport5more vulnerable than 5% of US census tracts
Walkability5.5 out of 20Least walkable
Nearby ZIP codes

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

21754 Ijamsville, MD4.9 km away
21774 New Market, MD6.9 km away
21771 Mount Airy, MD7.8 km away
20872 Damascus, MD8.9 km away
21704 Frederick, MD11.5 km away
20871 Clarksburg, MD12.8 km away
21701 Frederick, MD12.9 km away
21762 Libertytown, MD14.6 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.

Frederick County100% of this ZIP code's land area
Time zoneEastern (UTC-05:00 standard)
Daylight saving timeObserved
Land area11.45 sq mi
Water area0.01 sq mi
Population density683 people per sq mi
Latitude, longitude39.3512, -77.2494

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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