20851 ZIP Code
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ZIP code 20851 covers Rockville, Maryland, with a population of about 14,660 and a median household income of $113,951.
- Population
- 14,6605,782 per square mile
- Median age
- 38.6about the US average
- Median household income
- $113,9511.1× the Maryland median
- Poverty rate
- 9.2%3.2 points below the US average
- Typical home value
- $544,205up 12.8% in five years
- Median rent
- $1,9241.2× the Maryland median
- Degree or higher
- 41.4%6.4 points above the US average
- Homeownership
- 56.7%8.3 points below the US average
- Time zone
- Eastern UTC-05:00observes daylight saving time
- Businesses
- 178
Where 20851 is
Rockville, 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
| Population | 14,660 |
|---|---|
| Median age | 38.6 |
| Family households | 72.4% |
| Born outside the US | 36.7% |
| Speaks a language other than English at home | 53.9% |
| White (non-Hispanic) | 28% |
| Black (non-Hispanic) | 11.4% |
| Asian (non-Hispanic) | 13.7% |
| Hispanic or Latino | 42.2% |
| Veterans | 3.9% |
Income and poverty
American Community Survey 2019–2023 five-year estimates
| Median household income | $113,951 |
|---|---|
| Income per person | $47,505 |
| Poverty rate | 9.2% |
| Households on SNAP or cash assistance | 13% |
Household income distribution
| Under $10k | |
|---|---|
| $10–15k | |
| $15–20k | |
| $20–25k | |
| $25–30k | |
| $30–35k | |
| $35–40k | |
| $40–45k | |
| $45–50k | |
| $50–60k | |
| $60–75k | |
| $75–100k | |
| $100–125k | |
| $125–150k | |
| $150–200k | |
| $200k or more |
Income as declared to the IRS
Filed returns rather than survey responses, so this counts tax units and not households.
| Tax returns filed | 7,570 |
|---|---|
| Mean adjusted gross income | $70,083 |
| Returns declaring $200,000 or more | 5.7% |
| Returns, under $25k | 30.8% |
| Returns, $25k–$50k | 21.8% |
| Returns, $50k–$75k | 13.6% |
| Returns, $75k–$100k | 9.9% |
| Returns, $100k–$200k | 18.2% |
| Returns, $200k or more | 5.7% |
Housing
American Community Survey 2019–2023 five-year estimates
| Median home value | $523,800 |
|---|---|
| Median gross rent | $1,924 |
| Rent as a share of household income | 30.7% |
| Owner-occupied | 56.7% |
| Vacant homes | 3.6% |
| Median year built | 1958 |
What the homes are
| Detached house | |
|---|---|
| Attached house | |
| 2 to 4 units | |
| 5 to 19 units | |
| 20 or more units |
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 | $544,205as of 2026-07 |
|---|---|
| Typical home value, 1 year | down 1.2% |
| Typical home value, 5 years | up 12.8% |
| Typical home value, 10 years | up 48.7% |
| Typical asking rent | $2,897as of 2026-07 |
$168,780 in 2000 to $544,205 in 2026.
Work, commuting and education
American Community Survey 2019–2023 five-year estimates
| Unemployment rate | 3.8% |
|---|---|
| Bachelor's degree or higher | 41.4% |
| High school diploma or higher | 84.6% |
| Works from home | 23.6% |
| Drives to work alone | 51.6% |
| Takes public transport | 14.2% |
| Commutes 45 minutes or more | 28.2% |
Health
CDC PLACES 2025 release, model-based estimates. These are modelled small-area estimates for adults, not counts of diagnosed cases.
| Obesity | 26.9% 6.5 pts below the national average of 33.4% |
|---|---|
| Diagnosed diabetes | 9.9% 2.1 pts below the national average of 12% |
| Currently smokes | 8.7% 4.5 pts below the national average of 13.2% |
| High blood pressure | 28.5% 5.6 pts below the national average of 34.1% |
| Fair or poor general health | 17.1% 3.2 pts below the national average of 20.3% |
| No health insurance (18–64) | 12.5% 1.2 pts above the national average of 11.3% |
| Depression | 18.2% 3.7 pts below the national average of 21.9% |
| No leisure-time physical activity | 21.3% 4.1 pts below the national average of 25.4% |
| Arthritis | 18% 7.1 pts below the national average of 25.1% |
| Binge drinking | 14.8% 1.2 pts below the national average of 16% |
| Taking blood pressure medication | 70.8% 3.9 pts below the national average of 74.7% |
| Cancer (non-skin) | 5.6% 2.1 pts below the national average of 7.7% |
| Current asthma | 9.1% 1.3 pts below the national average of 10.4% |
| Coronary heart disease | 4.5% 1.7 pts below the national average of 6.2% |
| Routine check-up in past year | 73.4% 3.3 pts below the national average of 76.7% |
| Cholesterol screening | 88.1% 2.2 pts above the national average of 85.9% |
| Cognitive disability | 12% 2.8 pts below the national average of 14.8% |
| Colorectal screening | 63.9% same as the national average of 64.3% |
| COPD | 4.3% 2.3 pts below the national average of 6.6% |
| Visited a dentist | 62.3% 1 pts above the national average of 61.3% |
| Any disability | 23.3% 7.4 pts below the national average of 30.7% |
| Lacks emotional support | 24.3% 0.5 pts below the national average of 24.8% |
| Food insecurity | 15.6% 1.5 pts below the national average of 17.1% |
| Received food stamps | 10% 4.3 pts below the national average of 14.3% |
| Hearing disability | 4.8% 1.9 pts below the national average of 6.7% |
| High cholesterol | 38.6% 2.4 pts above the national average of 36.2% |
| Housing insecurity | 13.4% same as the national average of 13.8% |
| Independent living disability | 6% 2.4 pts below the national average of 8.4% |
| Lacks transport | 7.5% 1.7 pts below the national average of 9.2% |
| Loneliness | 34.7% same as the national average of 34.4% |
| Mammography use | 77.8% 1.9 pts above the national average of 75.9% |
| Poor mental health (14+ days) | 13.7% 3.1 pts below the national average of 16.8% |
| Mobility disability | 9.2% 4.8 pts below the national average of 14% |
| Poor physical health (14+ days) | 11% 2.5 pts below the national average of 13.5% |
| Self-care disability | 2.8% 1.2 pts below the national average of 4% |
| Utility shut-off threat | 7.1% 1.7 pts below the national average of 8.8% |
| Sleeps under 7 hours | 35.6% 0.8 pts below the national average of 36.4% |
| Stroke | 2.5% 0.9 pts below the national average of 3.4% |
| All natural teeth lost | 10.9% 2.1 pts below the national average of 13% |
| Vision disability | 4.4% 1.2 pts below the national average of 5.6% |
Business and employment
Census ZIP Code Business Patterns 2022
| Business establishments | 178 |
|---|---|
| People employed | 1,177 |
| Annual payroll | $56,051,000 |
Natural hazard risk
FEMA National Risk Index, estimated for this ZIP code from census tract data — the NRI is not published per ZIP.
| Overall risk | Higher than 4.9% of US census tracts |
|---|---|
| FEMA rating | Very Low |
| Expected annual loss | 5.1 out of 100 |
| Community resilience | 51.7 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.
| Winter weather | 78.9Relatively High at its worst in this ZIP code |
|---|---|
| Hurricane | 65.4Relatively Low at its worst in this ZIP code |
| Hail | 57.1Relatively Low at its worst in this ZIP code |
| Heat wave | 53.4Relatively Moderate at its worst in this ZIP code |
| Landslide | 52Very Low at its worst in this ZIP code |
| Earthquake | 49.8Relatively Low at its worst in this ZIP code |
| Strong wind | 47.8Relatively Moderate at its worst in this ZIP code |
| Cold wave | 34.7Relatively Low at its worst in this ZIP code |
| Lightning | 31.7Relatively Low at its worst in this ZIP code |
| Tornado | 27.7Relatively Low at its worst in this ZIP code |
| Wildfire | 23.8Very Low at its worst in this ZIP code |
| Ice storm | 14.1Very Low at its worst in this ZIP code |
| River flooding | 6.2Very 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 ZIP | Maryland | United States | |
|---|---|---|---|
| Median household income | $113,951 | $101,652 | $78,538 |
| Income per person | $47,505 | $51,689 | $43,289 |
| Poverty rate | 9.2% | 9.3% | 12.4% |
| Median home value | $523,800 | $397,700 | $303,400 |
| Median gross rent | $1,924 | $1,662 | $1,348 |
| Homeownership | 56.7% | 67.5% | 65% |
| Bachelor's degree or higher | 41.4% | 42.7% | 35% |
| Unemployment rate | 3.8% | 4.9% | 5.2% |
| Works from home | 23.6% | 17.2% | 13.5% |
| Born outside the US | 36.7% | 16.3% | 13.9% |
| Median age | 38.6 | 39.3 | 38.7 |
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 station | ROCKVILLE 1 NE, MD US3.5 km away |
|---|---|
| Rain in a year | 41 in |
Average high and low by month
| January | 42.2°F / 26.9°F3.11 in rain |
|---|---|
| February | 45°F / 28.4°F2.6 in rain |
| March | 53.7°F / 35.9°F3.66 in rain |
| April | 65.9°F / 45.6°F3.23 in rain |
| May | 74.3°F / 54.9°F3.55 in rain |
| June | 82.2°F / 63.6°F3.96 in rain |
| July | 87.1°F / 68.8°F3.98 in rain |
| August | 84.9°F / 67°F3.05 in rain |
| September | 77.5°F / 60°F4.01 in rain |
| October | 65.9°F / 48°F3.52 in rain |
| November | 55.7°F / 38.2°F3.27 in rain |
| December | 46°F / 30.9°F3.38 in rain |
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 supermarket | None of this ZIP code |
|---|---|
| Far from a supermarket | None of this ZIP code |
| No vehicle and far from a supermarket | None 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%.
| Montgomery County Public Schools | 100% 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 vulnerability | 58more vulnerable than 58% of US census tracts |
|---|---|
| Socioeconomic status | 56more vulnerable than 56% of US census tracts |
| Household characteristics | 51more vulnerable than 51% of US census tracts |
| Racial and ethnic minority status | 78more vulnerable than 78% of US census tracts |
| Housing type and transport | 51more vulnerable than 51% of US census tracts |
| Walkability | 13.4 out of 20Above average |
Nearby ZIP codes
The closest ZIP codes by centre point, which is not the same as sharing a border.
| 20847 Rockville, MD | 2.7 km away |
|---|---|
| 20849 Rockville, MD | 2.7 km away |
| 20857 Rockville, MD | 2.7 km away |
| 20853 Rockville, MD | 2.8 km away |
| 20852 Rockville, MD | 3 km away |
| 20883 Gaithersburg, MD | 3.2 km away |
| 20850 Rockville, MD | 4 km away |
| 20896 Garrett Park, MD | 5.1 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.
| Montgomery County | 100% of this ZIP code's land area |
|---|---|
| Time zone | Eastern (UTC-05:00 standard) |
| Daylight saving time | Observed |
| Land area | 2.54 sq mi |
| Population density | 5,782 people per sq mi |
| Latitude, longitude | 39.0763, -77.1234 |
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.