ZIP Code Tabulation Area · Virginia

ZIP Code 20124: Union Mill, VA

ZIP Code 20124 (Union Mill, Fairfax County, Virginia) has an estimated 14,375 residents in 4,825 households. The median household income is $221,060, the median home value is $884,800 and the median gross rent is $2,378/mo. Figures are U.S. Census Bureau American Community Survey 2020–2024 5-year estimates for the matching ZIP Code Tabulation Area.

American Community Survey 2020–2024 5-year estimates · Updated

Total population

14,375

Margin of error ±1,393

Median household income

$221,060

Margin of error ±$22,427

Median home value

$884,800

Margin of error ±$19,265

Median gross rent

$2,378/mo

Margin of error ±$147

Median age

47.7 yrs

Margin of error ±2.0 yrs

Mean travel time to work

31.9 min

Margin of error ±7.3 min

How ZIP 20124 compares with Virginia and the U.S.

State and national figures are the Census Bureau's own estimates for those areas from the same ACS release, not averages of ZIP codes.

Median age

ZIP 2012447.7 yrsVirginia39.0 yrsUnited States38.9 yrs

Median household income

ZIP 20124$221,060Virginia$93,170United States$80,734

Per capita income

ZIP 20124$93,604Virginia$50,666United States$44,673

Poverty rate

ZIP 201244.0%Virginia9.9%United States12.5%

Unemployment rate

ZIP 201244.7%Virginia4.3%United States5.2%

Bachelor's degree or higher

ZIP 2012474.4%Virginia42.2%United States35.7%

Median home value

ZIP 20124$884,800Virginia$383,700United States$332,700

Median gross rent

ZIP 20124$2,378/moVirginia$1,579/moUnited States$1,413/mo

Owner-occupied homes

ZIP 2012492.4%Virginia67.3%United States65.2%

Mean travel time to work

ZIP 2012431.9 minVirginia27.3 minUnited States26.4 min

Worked from home

ZIP 2012431.2%Virginia18.3%United States15.1%

All figures for ZIP 20124

Each estimate has a 90% margin of error: the true value is likely within that range. * marks estimates with a large margin of error (a coefficient of variation above 30%, or ±10 percentage points or more for rates).

ZIP 20124 — ACS 2020–2024 5-year estimates
MeasureZIP 20124Margin of errorVirginiaUnited States
Total population14,375±1,3938,705,170334,922,499
Median age47.7 yrs±2.0 yrs39.0 yrs38.9 yrs
Households4,825±4343,365,732129,227,496
Median household income$221,060±$22,427$93,170$80,734
Per capita income$93,604±$8,309$50,666$44,673
Poverty rate4.0%±1.6 pts9.9%12.5%
Unemployment rate4.7%±2.2 pts4.3%5.2%
Bachelor's degree or higher74.4%±3.4 pts42.2%35.7%
Median home value$884,800±$19,265$383,700$332,700
Median gross rent$2,378/mo±$147$1,579/mo$1,413/mo
Owner-occupied homes92.4%±2.4 pts67.3%65.2%
Mean travel time to work31.9 min±7.3 min27.3 min26.4 min
Worked from home31.2%±1.3 pts18.3%15.1%

Race and Hispanic or Latino origin

Shares of the total population by the Census Bureau's race and Hispanic or Latino origin categories (table B03002), listed in the Census Bureau's order. People self-identify on the survey.

Population by race and Hispanic or Latino origin, ZIP 20124
GroupZIP 20124VirginiaUnited States
White alone, not Hispanic or Latino55.1%58.4%57.4%
Black or African American alone, not Hispanic or Latino2.7%18.3%11.9%
American Indian and Alaska Native alone, not Hispanic or Latino0.0%0.1%0.5%
Asian alone, not Hispanic or Latino28.4%6.9%5.9%
Native Hawaiian and Other Pacific Islander alone, not Hispanic or Latino0.1%0.1%0.2%
Some other race alone, not Hispanic or Latino1.5%0.6%0.6%
Two or more races, not Hispanic or Latino5.7%4.7%4.3%
Hispanic or Latino (of any race)6.5%11.0%19.3%

Where ZIP 20124 is

State
Virginia
Main county
Fairfax County
Largest overlapping place
Union Mill (37% of the ZIP's land area)
Land area
21.69 sq mi· about 663 people per sq mi

County and place names come from the Census Bureau's 2020 ZCTA relationship files. A ZIP code's mailing city, set by the U.S. Postal Service, can differ from these names.

Other ZIP codes in Fairfax County

20120 Bull Run, VA20121 Bull Run, VA20151 Chantilly, VA20170 Herndon, VA20171 Franklin Farm, VA20190 Reston, VA20191 Reston, VA20194 Reston, VA22003 Annandale, VA22015 Burke, VA22027 Dunn Loring, VA22030 Braddock, VA22031 Mantua, VA22032 Kings Park West, VA22033 Fair Oaks, VA22039 Fairfax Station, VA22041 Bailey's Crossroads, VA22042 West Falls Church, VA22043 Idylwood, VA22044 Lake Barcroft, VA22060 Fort Belvoir, VA22066 Great Falls, VA22079 Mason Neck, VA22101 McLean, VA

See every ZIP code in Virginia, or compare ZIP 20124 with another ZIP code.

Census figures describe residents as a group and cannot tell you about any one home or street. For a specific address, check local government and housing records.

About ZIP codes and ZCTAs: the Census Bureau publishes statistics for ZIP Code Tabulation Areas, which approximate USPS ZIP code delivery areas. Learn how they differ.

Sources

  • U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, detailed tables B01003, B01002, B11001, B19013, B19301, B17001, B23025, B15003, B25077, B25064, B25003, B08013, B08303, B08301, B03002 — snapshot Oct 26, 2026.
  • U.S. Census Bureau, 2020 ZCTA5 relationship files (county and place).
  • Data: U.S. Census Bureau, American Community Survey 5-year estimates (detailed tables) and 2020 Census ZCTA relationship files. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. These agencies do not endorse OpenZIP.