Rockville, MD · standard

ZIP Code 20851

Montgomery County, Maryland — Census ACS demographics, housing tenure, and business patterns, benchmarked against every US ZIP.

Reviewed by PlainZIP Editorial Team, ZIP Code Data Editors · June 13, 2026

14,191
2,316/sq mi: $126,411
Median income: $568,900
Median home value: 46.2%
Bachelor's or higher

The verdict

Rockville pairs a top-decile household income with top-decile home values, in a suburban-density, mixed-tenure area.

Top 8%
household income, US ZIPs: Top 10%
home value, US ZIPs: 2,316
people per sq mi: 58%
owner-occupied homes

Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 20851 against every reporting US ZIP.

ZIP code 20851 is classified by USPS as a standard delivery area and covers roughly 6.1 square miles in Rockville, Montgomery County, Maryland. The area is home to 14,191 residents, producing a population density of 2,316 people per square mile, and falls within the New York time zone. These USPS and Census boundary values drive every downstream statistic on this page, including the benchmarks that compare 20851 against Maryland and the nation.

On the economic side, the median household income for ZIP 20851 sits at $126,411 (11% above the Maryland average), while per-capita income is $51,567. The poverty rate stands at 9.1% and the unemployment rate at 3.0%. On housing, the median home value is $568,900 (27% above the state average) with median rent at $2,043 per month, and 57.5% of occupied units are owner-occupied, a direct signal of whether 20851 behaves more like a homeowner neighborhood or a renter-heavy ZIP.

Education and household profile round out the picture: 46.2% of adults hold a bachelor's degree or higher, the median age is 38.6, and the average commute is 32 minutes. We also surface 10 nearby ZIP codes within roughly 10 miles and 6 additional ZIPs sharing Montgomery County, so you can benchmark 20851 against its immediate geography rather than a national average alone. Every figure is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates, HUD Fair Market Rents, and FHFA Home Price Index data, no estimates, no proprietary scoring. Verify with HUD →

Top industries in ZIP 20851

Construction

32
Other services (except public administration)

23
Retail trade

22
Professional, scientific, and technical services

20
Health care and social assistance

18

What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.

Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + HUD FMR + FHFA HPI ACS demographics, ZBP business establishments, HUD Fair Market Rents, FHFA HPI for ZIP 20851, Rockville, MD · 2023 Accessed 2026-06-13 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; HUD FMR + FHFA HPI updated quarterly/annually.

Quick Facts

14,191

Population

6.1

Area (sq mi)

2,316

People / sq mi

New York

Time Zone

standard

ZIP Type

Neighborhood Scorecard

Get an A-F grade across income, safety, housing, rent, education, commute, and childcare for this ZIP code.

View Scorecard →

Who lives in ZIP 20851?

38.6

Median Age

50.5%

Male

49.5%

Female

38.5%

Foreign-Born

White 30.7%

African American 11.4%

Asian 12.9%

American Indian or Alaska Native 1.3%

Native Hawaiian or Pacific Islander 0.0%

Two or More Ethnicities 20.2%

Hispanic or Latino 44.1%

Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

How much do residents earn?

$126,411

Median Household Income

+11% vs state

$51,567

Per Capita Income

9.1%

Poverty Rate

3.0%

Unemployment Rate

31.8 min

Mean Commute Time

How ZIP 20851 ranks nationally

Household income vs. every US ZIP code

Median household income — the full national distribution, with this ZIP marked

$126,411 Top 8% higher than 92% of 30,318 US ZIPs

Each bar is a $20K-wide band; taller bars hold more US ZIPs. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Census Bureau — ACS 5-Year Estimates · 2019–2023

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

What is the education profile here?

High School Graduate or Higher 65.9%

Bachelor's Degree or Higher 46.2%

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

What does housing look like?

5,338

Total Housing Units

5,155

Occupied Units

183

Vacant Units

2.89

Avg Household Size

Occupancy Type

Owner 57.5%

Renter 42.5%

$568,900

Median Home Value

+27% vs state

$2,043

Median Rent

1959

Median Year Built

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

How have home values changed over time?

FHFA House Price Index, annual appreciation data based on repeat sales and appraisals

+5.1%

YoY Change (2024)

319

HPI Index (2000 = 100)

+219%

Total Change Since 2000

Home values in ZIP 20851 have increased 5.1% over the past year (2024). Since 2000, this ZIP has seen +219% cumulative appreciation.

Year	Annual Change	HPI Index
2020	+2.2%	241
2021	+10.6%	266
2022	+9.1%	291
2023	+4.4%	303
2024	+5.1%	319

Source: Federal Housing Finance Agency (FHFA) House Price Index, All-Transactions, Five-Digit ZIP Codes (Developmental Index). Index base = 100 in year 2000. Data through 2024. ZIP codes with few transactions may show missing values.

What businesses operate in this ZIP?

Census Bureau data shows 168 business establishments in ZIP 20851, employing approximately 1,180 people with a combined annual payroll of $60,712,000.

168

Businesses

1,180

Employees

$60.7M

Annual Payroll

Industry Sectors

Industry	Establishments	% of Total
Construction	32	19.1%
Other services (except public administration)	23	13.7%
Retail trade	22	13.1%
Professional, scientific, and technical services	20	11.9%
Health care and social assistance	18	10.7%
Accommodation and food services	16	9.5%
Administrative and support and waste management and remediation services	11	6.5%
Real estate and rental and leasing	6	3.6%
Manufacturing	4	2.4%
Educational services	4	2.4%
Arts, entertainment, and recreation	3	1.8%

Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.

Nearby ZIP Codes

Want a side-by-side? Compare 20851 vs 20852 →

20906

64,696
20850

46,340
20852

40,365
20817

36,240
20853

29,673
20814

27,642
20895

19,054
20855

14,295
20851

14,191

What this shows Among its immediate neighbors, ZIP 20851 ranks #9 by population — useful context the national average alone can't give.

20896

$250,001
20817

$249,332
20895

$173,625
20853

$159,080
20814

$150,996
20855

$149,110
20880

$134,583
20851

$126,411
20850

$125,950

What this shows By household income, ZIP 20851 ranks #8 of 9 neighboring ZIPs — local affluence varies block to block, not just metro to metro.

ZIP Code	City	Population	Distance
20852	Rockville, MD	40,365	1.9 mi
20853	Rockville, MD	29,673	2.2 mi
20855	Derwood, MD	14,295	4.1 mi
20896	Garrett Park, MD	906	3.3 mi
20850	Rockville, MD	46,340	3.3 mi
20906	Silver Spring, MD	64,696	3.5 mi
20814	Bethesda, MD	27,642	5.2 mi
20895	Kensington, MD	19,054	4.3 mi
20817	Bethesda, MD	36,240	5.7 mi
20880	Washington Grove, MD	450	5.1 mi

More ZIP Codes in Montgomery County

Montgomery County Rockville, MD Maryland

Frequently Asked Questions

What county is ZIP code 20851 in? ▼

ZIP code 20851 (Rockville) is located in Montgomery County, Maryland. Montgomery County contains multiple ZIP codes, see the full list at /counties/montgomery-md.

What is the population of ZIP code 20851? ▼

ZIP code 20851 in Rockville, MD has a population of 14,191 according to the Census Bureau ACS 2023 estimates.

What is the median household income in ZIP 20851? ▼

The median household income in ZIP 20851 is $126,411, which is 66% above the national average of $76,288.

What is the average home value in ZIP 20851? ▼

The median home value in ZIP 20851 is $568,900, which is 105% above the national average of $278,155.

What is the demographic makeup of ZIP 20851? ▼

The largest racial group in ZIP 20851 is White at 30.7%. Hispanic or Latino residents make up 44.1% of the population.

How many businesses are in ZIP code 20851? ▼

ZIP code 20851 has 168 business establishments employing approximately 1,180 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.

What are the main industries in ZIP code 20851? ▼

The top industries by establishment count in ZIP 20851 are: Construction (32), Other services (except public administration) (23), Retail trade (22). There are 11 industry sectors represented in total.

How have home values changed in ZIP code 20851? ▼

According to the FHFA House Price Index, home values in ZIP 20851 increased by 5.1% in 2024. Since 2000, home values in this ZIP have appreciated by approximately 219%. This is a developmental index based on repeat sales and appraisal data from Fannie Mae and Freddie Mac.

What is the education level in ZIP code 20851? ▼

In ZIP code 20851, 65.9% of residents aged 25+ have a high school diploma or higher, and 46.2% hold a bachelor's degree or higher. These figures come from the Census Bureau ACS 5-Year Estimates (2023).

What is the average commute time in ZIP 20851? ▼

The mean commute time for workers in ZIP code 20851 is 31.8 minutes according to Census ACS data. The national average is roughly 26 minutes, so commuters here spend more time traveling to work than typical.

What percentage of residents own vs. rent in ZIP 20851? ▼

In ZIP code 20851, approximately 57.5% of occupied housing units are owner-occupied and 42.5% are renter-occupied, based on Census ACS 2023 data.

What is the poverty rate in ZIP code 20851? ▼

The poverty rate in ZIP code 20851 is 9.1% according to Census Bureau ACS 2023 estimates. This measures the percentage of the population living below the federal poverty threshold.