20851 ZIP Code — Rockville, MD
Montgomery County, Maryland
ZIP code 20851 is located in Rockville, Maryland, within Montgomery County. It covers approximately 2.54 square miles and serves a population of 14,659 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 301/240.
About ZIP code 20851
The housing stock consists of a mix of housing types. Most homes were built in the 1950s, giving the area an established character. Median home value is $466,700. Owner-occupancy sits near the national average at 60%.
Median household income is $107,578.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 31 minutes is near the national average.
Educational attainment is near the national average, with 41% of residents holding a bachelor's degree or higher.
Notable community characteristics include Spanish spoken in 27% of households.
14,659
population
2.54
sq mi land
Standard
ZIP type
Eastern (ET)
timezone
20851 ZIP code map
Cities in ZIP code 20851
Below are the cities the US Postal Service accepts for ZIP code 20851. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Rockville | Preferred |
Nearby ZIP codes
20857 Rockville (1.6 mi)
20852 Rockville (1.8 mi)
20853 Rockville (2.4 mi)
20906 Silver Spring (3.5 mi)
20897 Suburb Maryland Fac (3.6 mi)
20850 Rockville (3.7 mi)
20895 Kensington (4.2 mi)
20855 Derwood (4.4 mi)
20902 Silver Spring (4.9 mi)
20877 Gaithersburg (5.2 mi)
20814 Bethesda (5.2 mi)
20892 Bethesda (5.5 mi)
Demographics
updated 05/2026
| Population | |
|---|---|
| Total population | 14,659 |
| Population density | 5,771 / sq mi |
| State FIPS | 24 |
| County FIPS | 031 |
| Geography | |
|---|---|
| Land area | 2.54 sq mi |
| Water area | 0.00 sq mi |
| Latitude | 39.0782 |
| Longitude | -77.1238 |
| Timezone | Eastern (ET) |
| Area code | 301/240 |
Total population by age
Gender
Race & ethnicity
Economics
updated 05/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 27.3% | 20.6% | 28.2% |
| $50k – $100k | 26.9% | 24.2% | 28.2% |
| $100k – $200k | 33.0% | 31.9% | 30.1% |
| Over $200k | 12.8% | 23.3% | 13.4% |
Demographics & statistics
14,659
Population
5,771
People per sq mi
36.0
Median age
$107,578
Median household income
$45,623
Per capita income
$466,700
Median home value
$1,900
Median monthly rent
59.6%
Home ownership
9.6%
Poverty rate
3.5%
Unemployment
3,263
Housing units
41.4%
Bachelor's or higher
Age distribution
Male
Female
391
Under 5
372
401
5–9
381
454
10–14
431
487
15–19
462
525
20–24
498
1,339
25–34
1,272
975
35–44
926
1,088
45–54
1,034
444
55–59
421
496
60–64
472
641
65–74
608
186
75–84
176
92
85+
87
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 2,890 | 19.7% |
| 18 and over | 11,769 | 80.3% |
| 65 and over | 1,790 | 12.2% |
| Median age | 36.0 years | |
Race & ethnicity
Hispanic or Latino
25.8%
White
25.4%
Other race
17.7%
Asian
11.9%
Two or more races
10.1%
Black or African American
8.6%
American Indian / Alaska Native
0.5%
| Group | Count | % |
|---|---|---|
| Hispanic or Latino | 5,099 | 25.8% |
| White | 5,012 | 25.4% |
| Other race | 3,503 | 17.7% |
| Asian | 2,357 | 11.9% |
| Two or more races | 1,989 | 10.1% |
| Black or African American | 1,705 | 8.6% |
| American Indian / Alaska Native | 93 | 0.5% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 27.3% | 20.6% | 28.2% |
| $50k – $100k | 26.9% | 24.2% | 28.2% |
| $100k – $200k | 33.0% | 31.9% | 30.1% |
| Over $200k | 12.8% | 23.3% | 13.4% |
Under $10k
2.9%
$10k–$15k
0.6%
$15k–$25k
2.1%
$25k–$35k
3.6%
$35k–$50k
12.1%
$50k–$75k
13.9%
$75k–$100k
12.4%
$100k–$150k
22.1%
$150k–$200k
14.6%
$200k+
15.7%
| Range | % of households |
|---|---|
| Under $10k | 2.9% |
| $10k–$15k | 0.6% |
| $15k–$25k | 2.1% |
| $25k–$35k | 3.6% |
| $35k–$50k | 12.1% |
| $50k–$75k | 13.9% |
| $75k–$100k | 12.4% |
| $100k–$150k | 22.1% |
| $150k–$200k | 14.6% |
| $200k+ | 15.7% |
| Median income | $107,578 |
Housing
Home values
Under $50k
2.3%
$50k–$100k
0.5%
$150k–$200k
0.3%
$200k–$300k
2.7%
$300k–$500k
59.0%
$500k–$1M
34.0%
$1M+
1.2%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $466,700 |
| Median rent / month | $1,900 |
| Owner occupied | 59.6% |
| Renter occupied | 40.4% |
| Vacant | 4.4% |
| Single-family detached | 66.3% |
| Large apartment buildings | 9.6% |
| Mobile homes | 0.0% |
| Median rooms | 6.0 |
| Avg household size (owned) | 2.78 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.0% |
| 2010–2019 | 3.5% |
| 2000–2009 | 2.4% |
| 1990–1999 | 5.3% |
| 1980–1989 | 11.0% |
| 1970–1979 | 6.4% |
| 1960–1969 | 16.0% |
| 1950–1959 | 47.1% |
| 1940–1949 | 5.4% |
| 1939 or earlier | 2.9% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 1.7% |
| 1 bedroom | 8.7% |
| 2 bedrooms | 17.6% |
| 3 bedrooms | 38.2% |
| 4 bedrooms | 27.8% |
| 5+ bedrooms | 6.0% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 7.4% |
| 1 vehicle | 35.8% |
| 2 vehicles | 31.5% |
| 3 or more | 25.3% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 76.5% |
| Electricity | 22.6% |
| Propane / LP gas | 0.2% |
| Fuel oil | 0.2% |
| Wood | 0.2% |
| Solar | 0.2% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 2,271 | 44.7% |
| Cohabiting couple | 282 | 5.6% |
| Male householder, no spouse | 1,151 | 22.7% |
| Female householder, no spouse | 1,377 | 27.1% |
| Households with children under 18 | 1,604 | 31.6% |
| Households with seniors (65+) | 1,378 | 27.1% |
| Average household size | 2.88 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 43.4% | 36.0% |
| Married | 45.7% | 43.5% |
| Separated | 2.8% | 2.1% |
| Widowed | 2.3% | 6.5% |
| Divorced | 5.7% | 11.9% |
Education
Less than 9th grade
5.8%
Some HS, no diploma
10.1%
HS graduate
21.2%
Some college, no degree
15.5%
Associate's degree
6.1%
Bachelor's degree
21.9%
Graduate / professional
19.4%
| Metric | % |
|---|---|
| HS diploma or higher | 84.2% |
| Bachelor's or higher | 41.4% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 333 | 9.2% |
| Kindergarten | 204 | 5.6% |
| Elementary school | 1,359 | 37.6% |
| High school | 647 | 17.9% |
| College / grad school | 1,074 | 29.7% |
Employment
Industry of employment
Education & healthcare
19.1%
Professional & management
19.0%
Construction
13.6%
Arts, food & hospitality
13.3%
Retail trade
9.9%
Public administration
6.2%
Other services
5.2%
Finance & real estate
4.9%
Manufacturing
2.6%
Transportation & utilities
2.3%
Information
2.3%
Wholesale trade
1.7%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 40.4% |
| Service | 20.5% |
| Sales & office | 19.0% |
| Natural resources & construction | 12.8% |
| Production & transportation | 7.3% |
Employment type
| Type | % |
|---|---|
| Private sector | 72.8% |
| Government | 21.5% |
| Self-employed | 5.6% |
| Unpaid family workers | 0.2% |
Commute
| Method | % |
|---|---|
| Drive alone | 52.3% |
| Carpool | 6.5% |
| Public transit | 15.0% |
| Walk | 2.0% |
| Work from home | 19.5% |
| Other means | 4.8% |
| Avg commute (minutes) | 30.5 |
Poverty
All people
9.6%
Under 18 years
16.6%
18 and over
7.9%
Married-couple families
1.8%
Female-led households
6.2%
Income support
| Source | % of households |
|---|---|
| Social Security | 19.6% |
| Retirement income | 13.5% |
| Supplemental Security | 4.4% |
| Cash public assistance | 3.0% |
| Food stamps / SNAP | 12.3% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 22.8% |
| High blood pressure | 25.9% |
| High cholesterol | 30.6% |
| Diabetes | 8.3% |
| Heart disease | 4.4% |
| Stroke | 2.3% |
| Asthma | 8.4% |
| Arthritis | 16.8% |
| Kidney disease | 2.3% |
| Pulmonary disease | 4.5% |
| Cancer | 4.6% |
| Behavior / access | % |
|---|---|
| Smoking | 12.0% |
| Binge drinking | 13.4% |
| No physical activity | 20.6% |
| Less than 7 hrs sleep | 31.3% |
| Depression | 16.6% |
| Fair or poor health | 11.8% |
| Poor mental health | 12.9% |
| Poor physical health | 7.4% |
| No health insurance | 17.0% |
| Visited doctor (checkup) | 69.6% |
| Visited dentist | 61.6% |
| Cholesterol screening | 90.1% |
| Teeth loss | 10.3% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 449 | 3.8% |
| Disability | % |
|---|---|
| Any disability | 7.6% |
| Under 18 | 4.4% |
| 18–64 years | 6.0% |
| 65 and over | 21.6% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 71.4% |
| Public insurance | 27.9% |
| No insurance | 11.8% |
| Uninsured under 19 | 3.8% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 13,896 | 94.8% |
| Spanish | 3,749 | 27.0% |
| Other Indo-European | 2,634 | 19.0% |
| Asian & Pacific Islander | 311 | 2.2% |
| Other languages | 755 | 5.4% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 9,625 | 65.7% |
| Born in same state | 9,433 | 64.3% |
| Born in different state | 4,637 | 31.6% |
| Foreign born | 192 | 1.3% |
| Naturalized citizen | 5,034 | 34.3% |
| Not a US citizen | 2,763 | 54.9% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| French | 850 | 5.8% |
| Arab | 612 | 4.2% |
| Italian | 580 | 4% |
| English | 179 | 1.2% |
| Polish | 68 | 0.5% |
| Ancestry | Count | % |
|---|---|---|
| German | 40 | 0.3% |
| Irish | 36 | 0.2% |
| Norwegian | 25 | 0.2% |
| Dutch | 7 | 0% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 34.7% |
| Internet access | 96.3% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 20851
What city is ZIP code 20851 in?
ZIP code 20851 is primarily assigned to Rockville, Maryland.
What county is ZIP code 20851 in?
ZIP code 20851 falls within Montgomery County, Maryland.
Is Spanish widely spoken in ZIP code 20851?
Approximately 27% of households in ZIP code 20851 speak Spanish as a primary language.
What is the typical home value in ZIP code 20851?
The median home value in ZIP code 20851 is $466,700.
What is the median household income in ZIP code 20851?
The median household income in ZIP code 20851 is $107,578, above the national median of ~$75,000.
What is the population of ZIP code 20851?
ZIP code 20851 has an estimated population of 14,659 residents, with a density of 5,783 people per square mile.
What timezone is ZIP code 20851 in?
ZIP code 20851 observes the EST timezone.