ZIP Code 21791 in Union Bridge, MD

Data Last Updated: February 1, 2026
City:Union Bridge, Maryland
City Alias:Linwood
Counties:Carroll County [Primary]
Frederick County
Timezone:Eastern (GMT -05:00)
Local Time:10:02:50 PM
Population:5,292 [See All]
Area Codes:410 / 443 / 667
Classification:Standard [Normal Street Delivery]
Coordinates:39.5328, -77.1873
Land Area:46.04 sq mi
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Population & Demographics


ZIP Code 21791 has 5,292 residents and 1,976 households (average 2.68 persons per household). The median age is 42.0 years, older than the state (38.8) and older than the nation (38.8). The gender split is 50.0% male and 50.0% female, which is slightly higher than the state male share (48.2%). Largest groups are White (90.5%, much higher than the state average of 48.7% and well above the national average of 61.6%) and Hispanic or Latino (2.3%); Hispanic or Latino residents make up 2.3%, which is much lower than the national average (18.7%).

Explore More: Population Over Time By Age & Gender By Race By Gender Nativity & Citizenship

Source: U.S. Census 2020 Demographics & Housing Characteristics (DHC) and U.S. Census 2011-2024 American Community Survey (ACS) 5-Year Estimates.
2020 Population:5,292Source: Census DHC
2024 ACS Population Estimate:5,340Source: Census ACS
2026 ZC Population Estimate:4,856Source: ZIP-Codes.com
Population Density:114.9 people per sq mile
Average Income:$93,015Source: Census ACS
Households:1,976Source: Census DHC
Average House Value:$379,800Source: Census ACS
Persons Per Household:2.68Source: Census DHC
Average Family Size:2.76Source: Census ACS

Population Over Time (with 2010 & 2020 Census Benchmarks)


Group201020112102201320142015201620172018201920202021202220232024
Census ACS Population Estimate--5,5335,6785,6605,6435,7385,5325,5255,3285,2455,0804,7944,8554,7345,340
Decennial Census5,281------------------5,292--------
Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. DP05. DEMOGRAPHIC AND HOUSING ESTIMATES

Population by Age & Gender (Total, Male, Female)


Median Age: 42

Male Median Age: 42.3

Female Median Age: 41.5

Group< 55-910-1415-1920-2425-2930-3435-3940-4445-4950-5455-5960-6465-6970-7475-7980-8485+
Male172158149154163178163144111167172248178183149594555
Female182150149175128148165179129170170217175204107926044
Total35430829832929132632832324033734246535338725615110599
Source: U.S. Census Bureau (2020) Demographics & Housing Characteristics (DHC)

Population by Race


White:4,79093.14%
Black:1202.33%
Hispanic:*1222.37%
Asian:470.91%
American Indian:90.17%
Hawaiian:00%
Other:551.07%
Total:5,143100%
Source: U.S. Census Bureau (2020) Demographics & Housing Characteristics (DHC)
* NOTE: Hispanic or Latino is an ethnicity, not a race. This means individuals who identify as Hispanic will also be included in one of the race categories (such as White or Black). As a result, the totals shown here may exceed 100% when Hispanic is displayed alongside racial groups.

Gender Breakdown


GenderCount%Median Age
Males:2,64850.04%42.3 years
Females:2,64449.96%41.5 years
Total:5,292100%42.0 years
Source: U.S. Census Bureau (2020) Demographics & Housing Characteristics (DHC)

Nativity & Citizenship


Native, born in the United States:5,04794.51%
Native, born in PR, Island Areas, or abroad:1753.28%
Foreign born, naturalized U.S. citizen:1011.89%
Foreign born, not a U.S. citizen:172.21%
Total Population:5,340100%
Total Native Population:5,22297.79%
Total Foreign-born Population:1182.21%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP02. SELECTED SOCIAL CHARACTERISTICS
Note: Nativity and Citizenship derived from American Community Survey (ACS) 5-year estimates. Total Population listed here will not match official ZIP Code population totals, which are based on the Decennial Census.

Income & Employment


In 2024, the Median household income is $93,015, which is far above the national median ($78,538), is up $6,616 (7.7%) since 2011 and above its 2019 pre-pandemic level by $6,290. Family households earn a median of $97,955 versus $57,024 for nonfamily households (a difference of $40,931). By gender, male median income is $74,646 and female is $49,219, which is far less than the state female median ($68,044), with a current gap of $25,427 that has widened from 2011 to 2024. The labor-force participation rate is 64.1%, which is lower than the state rate (67.2%). The unemployment rate is 2.0%, which is markedly below the national rate (5.2%). The largest occupation group is Management (34.2%).

Explore More: Income Over Time Household Income Employment Status By Occupation

Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. Using data from Tables DP02, DP03, DP04 and DP05.

Median Income Over Time (Household, Family, Nonfamily, Male, Female)


Income Type20112012201320142015201620172018201920202021202220232024
Median Household Income$86,399$87,708$87,531$79,718$77,596$81,157$85,305$84,848$86,725$89,335$93,578$88,984$90,460$93,015
Median Family Income$91,316$93,278$88,616$83,138$83,060$89,545$92,466$100,168$103,140$107,847$112,442$107,813$101,458$97,955
Median NonFamily Income$48,603$48,466$50,804$42,708$39,375$30,278$34,583$43,026$50,217$55,068$57,703$58,068$57,604$57,024
Median Male Income$63,036$60,964$67,250$63,125$65,815$60,958$66,696$62,661$61,071$72,078$72,337$80,143$72,388$74,646
Median Female Income$38,750$37,596$43,214$42,250$45,528$53,354$54,406$51,898$51,167$56,367$55,357$53,906$47,000$49,219
Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. DP03. SELECTED ECONOMIC CHARACTERISTICS

Average Household Income


Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Employment Status


Employed:2,68162.15%
Unemployed:541.25%
Not In Labor Force:1,57936.60%
Total:4,314100%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Employment by Occupation (Civilian Employed Population, 16 and Over)


Management, business, science, and arts:91834.24%
Service:59222.08%
Sales and Office:50918.99%
Natural resources, construction, and maintenance:41015.29%
Production, transportation, and material moving:2529.40%
Total Civilian Employed Population:2,681100%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS.

Housing & Affordability


In 2024, the median home value is $379,800, which is considerably higher than the national median ($303,400), is up $44,100 (13.14%) since 2011 and above its 2019 pre-pandemic level by $54,900. The median gross rent is $1,457, which is well under the state median ($1,662), is up $608 (71.61%) since 2011 and above its 2019 pre-pandemic level by $388. Of occupied housing, owners make up 81.71% (76.24% with a mortgage, 23.76% free-and-clear) and renters 18.29% - making this ZIP Code more home ownership than the state and under national rental averages. The vacancy rate is 4.42%, which is markedly below the national rate (10.43%).

Explore More: Compare Home Value Home Value Over Time Rent & Over Time Housing Occupancy

Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. Using data from Table DP03, SELECTED ECONOMIC CHARACTERISTICS.

Median Home Value (Comparison)


Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP04. SELECTED HOUSING CHARACTERISTICS

Median Home Value Over Time


Group20112102201320142015201620172018201920202021202220232024
Median Home Value$335,700$328,100$319,800$285,700$280,400$307,300$311,400$313,200$324,900$336,600$326,600$349,900$370,300$379,800
Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. DP04. SELECTED HOUSING CHARACTERISTICS

Gross Rent Paid


Less than $500:71.94%
$500 to $999:6618.33%
$1,000 to $1,499:9426.11%
$1,500 to $1,999:10228.33%
$2,000 to $2,499:143.89%
$2,500 to $2,999:339.17%
$3,000 or more:30.83%
No Rent:4111.39%
Total:360100%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP04. SELECTED HOUSING CHARACTERISTICS

Median Gross Rent Over Time


Group20112102201320142015201620172018201920202021202220232024
Median Rent$849$890$995$945$949$925$897$1,053$1,069$972$1,139$1,156$1,320$1,457
Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. DP04. SELECTED HOUSING CHARACTERISTICS

Housing Occupancy


Owner Occupied (with mortgage):1,22662.30%
Owner Occupied (free and clear, no mortgage):38219.41%
Renter Occupied:36018.29%
Total Occupied Housing Units:1,968100%

Occupied Housing Units:1,96895.58%
Vacant Housing Units (not graphed):914.42%
Total Housing Units:2,059100%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP04. SELECTED HOUSING CHARACTERISTICS

Housing Type (Single-Family, Multi-Family, Other)


Single-Family Units:1,93994.17%
Multi-Family Units:1125.44%
Other Units:80.39%
Total Housing Units:2,059100%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP04. SELECTED HOUSING CHARACTERISTICS

Education, Health & Community


In 2024, 26.70% of adults (25+) have a bachelor's degree or higher, which is markedly below the state rate (42.70%). High school or higher is 92.30%, which is well above the national rate (89.40%). The uninsured rate is 10.60%, which is on par with the state rate (6.20%). The share of people in poverty is 3.90%, which is far lower than the national rate (8.70%), down 0.60 percentage points since 2011 and above its 2019 pre-pandemic level by 0.20 percentage points. Poverty has been broadly stable, which may reflect structural barriers or offsetting gains and setbacks. Among residents ages 3+, the largest enrollment group is elementary (49.73%). College enrollment is 7.32%, which is markedly below the state rate (28.00%), indicating the community may be more oriented toward vocational/trade or direct-to-workforce opportunities.

Explore More: Educational Attainment Health Insurance Poverty Over Time School Enrollment

Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. Using data from Tables DP02 and DP03.

Educational Attainment of Adults (25 and Older)


Less than 9th grade:882.45%
9th to 12th grade, no diploma:1875.21%
High school graduate (includes equivalency):1,44540.24%
Some college, no degree:71619.94%
Associate's degree:1955.43%
Bachelor's degree:57215.93%
Graduate or professional degree:38810.80%
Total:3,591100%
High school or higher:3,31692.34%
Bachelor's degree or higher:96026.73%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP02. SELECTED SOCIAL CHARACTERISTICS

Health Insurance Coverage by Type (Private, Public, Uninsured)


Private Insurance:3,91462.87%
Public Insurance:1,74828.08%
No Insurance:5649.06%
Total:6,226100%
Has Health Insurance:5,66290.94%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Percentage of People in Poverty Over Time (2011-2024)


Group20112102201320142015201620172018201920202021202220232024
% of People in Poverty4.5%3.9%2.4%4.2%4.0%5.3%4.9%6.2%3.7%5.4%4.6%4.9%3.9%3.9%
Source: U.S. Census 2011-2024 American Community Survey 5-Year Estimates. DP03. SELECTED ECONOMIC CHARACTERISTICS

Note: Counts of Families & People in poverty are not published at the ZIP Code level due to small sample sizes. Percentages shown are survey estimates from the American Community Survey (ACS). They may differ from official poverty statistics. The U.S. Census Bureau defines poverty status by comparing a family's or individual's total income with federal poverty thresholds that vary by family size and composition.

School Enrollment by Education Level (Ages 3 and Older)


Nursery School, Preschool:625.61%
Kindergarten:322.89%
Elementary school (grades 1-8):55049.73%
High school (grades 9-12):38134.45%
College or graduate school:817.32%
Total:1,106100%
Early Childhood:948.50%
K-12 (Primary & Secondary School):96387.07%
Source: U.S. Census 2020-2024 American Community Survey 5-Year Estimates. Table DP02. SELECTED SOCIAL CHARACTERISTICS

Business & Employment Statistics


ZIP Code 21791 supports both business and residential activity. According to the Business Census (2024), there are 98 business establishments, employing about 868 people with an annual payroll of $40,869,000. USPS data shows 1,812 residential mailboxes and 27 business mailboxes, reflecting local delivery coverage.

# Residential Mailboxes:1,812Source: USPS
# Business Mailboxes:27Source: USPS
Total Delivery Receptacles:2,115Source: USPS
Single Family Delivery Units:1,772Source: USPS
Multi Family Delivery Units:21Source: USPS
# of Businesses:98Source: CBP
1st Quarter Payroll:$10,092,000Source: CBP
Annual Payroll:$40,869,000Source: CBP
# of Employees:868Source: CBP

Geography, Land Area, & Statistical Classifications


ZIP Code 21791 is located in Carroll County, Maryland, within the Baltimore-Columbia-Towson, MD Metropolitan Statistical Area (CBSA 12580) and Maryland's 2nd and 6th Congressional Districts. This Metro area has a population of 2,710,489 people, about 0.20% of whom live in ZIP Code 21791. It covers 46.04 sq mi of land and a water area of 0.08 sq mi.

CBSA Name:Baltimore-Columbia-Towson, MDSource: Census
CBSA Number:12580Source: Census
CBSA Type:MetroSource: Census
CBSA Division:--Source: Census
CBSA Population:2,710,489Source: Census
MSA:Washington-Baltimore, DC-MD-VA-WV CMSASource: Census
Land Area:46.04 sq miSource: Census
Water Area:0.08 sq miSource: Census
Congressional District:02,06Source: USPS
Congressional Land Area:348.88, 1950.26 sq miSource: Census
PMSA:Baltimore, MD PMSASource: Census
Intro Date:< 2004-10Source: ZIP-Codes.com
Place FIPS Code:2479350Source: Census
Place Name:Union Bridge town; MarylandSource: Census

Adjacent & Nearby ZIP Codes


21792 | | 21790

Schools in ZIP Code 21791


ZIP Code 21791 is in the Carroll County Public Schools, which serves grades Pre-Kindergarten thru 12th. There are 2 public school(s) in this ZIP Code, and we have located 3 private school(s). It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.

Elmer A. Wolfe Elementary 119 North Main Street
Union Bridge, MD 21791
District: Carroll County Public Schools
Francis Scott Key High 3825 Bark Hill Road
Union Bridge, MD 21791
District: Carroll County Public Schools
Springdale Preparatory School 1000 Green Valley Rd
New Windsor, MD 21776
District: Private SchoolNearby
Springdale Preparatory School 1000 Green Valley Rd
New Windsor, MD 21776
District: Private SchoolNearby
Carroll Lutheran School 1738 Old Taneytown Rd
Westminster, MD 21158
District: Private SchoolNearby

Colleges & Post Secondary Schools near ZIP Code 21791


Carroll Community College 1601 Washington Rd
Westminster, MD 21157
Type: Post Secondary
Mcdaniel College 2 College Hill
Westminster, MD 21157
Type: Post Secondary
Mount St. Mary's University 16300 Old Emmitsburg Road
Emmitsburg, MD 21727-7799
Type: Post Secondary
Frederick Community College 7932 Opossumtown Pike
Frederick, MD 21702-2964
Type: Post Secondary
The Temple-A Paul Mitchell Partner School 22 W Church St
Frederick, MD 21701
Type: Post Secondary
Hood College 401 Rosemont Ave
Frederick, MD 21701
Type: Post Secondary

Sources & References


Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on February 1, 2026.

  1. U.S. Postal Service [Last Updated: 2/1/2026], https://www.usps.com
  2. ZIP-Codes.com Proprietary Data Enhancements [Updated: 2/1/2026], https://www.zip-codes.com
  3. U.S. Census [Updated: Varies], https://www.census.gov
    • U.S. Census Office of Management and Budget [Updated: As Released]
    • U.S. Census 2020 Demographic & Housing Characteristics (DHC) [Decennial] [Updated: 5/25/2023]
    • U.S. Census 2011-2024 American Community Survey 5-year estimates (ACS) [Annually] [Updated: Annually, As Released]
    • U.S. Census Business Patterns (CBD) [Annually] [Updated: Annually, As Released]
    • U.S. Census American National Standards Institute (ANSI) [Updated: As Released]
  4. U.S. Geological Survey [Updated: Varies], https://www.usgs.gov
  5. Centers for Medicare & Medicaid Services [Updated: Annually, As Released], https://www.cms.gov
  6. National Center for Education Statistics [Updated: 2/1/2026], https://nces.ed.gov