Residential delivery area · Maryland
ZIP Code 20851: Rockville, MD
ZIP code 20851 is in Rockville, Maryland, entirely in Montgomery County (Census 2020 ZIP-county file). About 15,000 people live there (Census Bureau, ACS 2020-2024), the least populous of Rockville's 4 residential ZIP codes. Median household income is $126,411 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Rockville (81%), North Bethesda (12%) and Aspen Hill (7%).
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Rockville · 4 residential ZIPs
- County
- Montgomery County
- Census places
- Rockville (81%); North Bethesda (12%) census-designated place; Aspen Hill (7%) census-designated place
- Metro area
- Washington-Arlington-Alexandria, DC-VA-MD-WV
- House district
- MD-8 119th Congress
- State
- Maryland
- Time zone
- Eastern
- Land area
- 2.5 sq mi · 5,894 people per sq mi
Where is ZIP code 20851?
20851 centers on 39.078°, -77.121° and covers 2.5 square miles of land. It borders 3 ZIP codes: 20852, 20853, 20850.
The map draws ZIP code areas only. For the streets inside 20851, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 20851 compare with the rest of Rockville?
| Measure | 20851 | In Rockville | In Montgomery County | In MD |
|---|---|---|---|---|
| People (ACS 2020-2024) | 14,946 | 4th of 4 | 31st of 53 | 152nd of 477 |
| Median household income | $126k | 2nd of 4 | 26th of 41 | 100th of 293 |
| Median home value | $569k | 4th of 4 | 27th of 41 | 64th of 320 |
Its median household income is higher than in 92% of U.S. residential ZIP codes, and it is denser than 95% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 20851?
The 2020 Census counted 14,327 people in 20851; the ACS, which samples households over 2020-2024, estimates 14,946. Between the 2010 and 2020 censuses its population grew 1.0% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 14,946
- 2020 Census count
- 14,327+1.0% since 2010 (14,191)
- Households
- 5,155
- Median age
- 38.6
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 20851?
Of the 14,946 people the ACS estimates in 20851, 20.0% are under 18 and 13.1% are 65 or older. The largest group by race and Hispanic origin is Hispanic or Latino (44.1%), then White (not Hispanic) (28.5%).
- Under 1820.0%
- 18 to 6466.9%
- 65 and older13.1%
- Hispanic or Latino44.1%
- White, not Hispanic28.5%
- Asian, not Hispanic12.1%
- Black, not Hispanic10.9%
- Other or two or more4.3%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 20851 earn?
Median household income is $126,411 (ACS 2020-2024), the 26th highest of the 41 ranked ZIP codes in Montgomery County. It is not measurably different from 2015-2019 ($111,490 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $126,411±$14,826
- Income per person
- $51,567
- Below the poverty line
- 9.1%
- Unemployed (of the labor force)
- 3.0%
- Adults 25+ with a bachelor's degree
- 46.2%
- Adjusted gross income per tax return, 2022
- $70,0837,570 returns; wages 80% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 20851?
FHFA's house price index for 20851, built from repeat sales and appraisals of the same homes, rose 65% from 2015 to 2025 and rose 37% from 2020 to 2025, and moved +3.3% in 2025.
- Median home value (owners' estimate)
- $568,900
- Median gross rent
- $2,043
- Homes owned by their occupants
- 57.5%
- Housing units
- 5,338
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 20851?
168 business establishments had a location in this ZIP code in 2023, 7 fewer than in 2018; the most are in construction (ZIP Code Business Patterns).
- Construction32
- Other services (except public administration)23
- Retail trade22
- Professional, scientific, and technical services20
- Health care and social assistance18
- Accommodation and food services16
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 20851?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 20852 | Rockville | 48,180 | $123k | 1.8 mi |
| 20853 | Rockville | 31,851 | $159k | 2.2 mi |
| 20850 | Rockville | 50,353 | $126k | 3.3 mi |
| 20896 | Garrett Park | 932 | $250k+ | 3.3 mi (near) |
| 20906 | Silver Spring | 70,595 | $98k | 3.6 mi (near) |
| 20855 | Derwood | 17,279 | $149k | 4.1 mi (near) |
| 20895 | Kensington | 19,184 | $174k | 4.2 mi (near) |
| 20902 | Silver Spring | 54,261 | $115k | 4.8 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.