21771 ZIP Code — Mount Airy, MD
Frederick County, Maryland
ZIP code 21771 is located in Mount Airy, Maryland, within Frederick County. It covers approximately 89.52 square miles and serves a population of 31,653 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 240/301.
About ZIP code 21771
The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1990s, giving the area an established character. Median home value is $501,800. Owner-occupancy is high at 93%, well above the national average.
Median household income is $148,909. The poverty rate of 3% is below the national average.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. An above-average commute of 36 minutes suggests many residents work outside the immediate area.
Educational attainment is high — 46% of residents hold a bachelor's degree or higher, well above the national average of 33%.
31,653
population
89.52
sq mi land
Standard
ZIP type
Eastern (ET)
timezone
21771 ZIP code map
Cities in ZIP code 21771
Below are the cities the US Postal Service accepts for ZIP code 21771. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Mount Airy | Preferred |
Nearby ZIP codes
21797 Woodbine (4.4 mi)
21770 Monrovia (5.7 mi)
20872 Damascus (6.7 mi)
21774 New Market (6.7 mi)
21738 Glenwood (9.4 mi)
20882 Gaithersburg (10 mi)
21776 New Windsor (10.1 mi)
21784 Sykesville (10.2 mi)
20871 Clarksburg (10.2 mi)
21737 Glenelg (10.8 mi)
21791 Union Bridge (11.1 mi)
21794 West Friendship (11.3 mi)
Demographics
updated 05/2026
| Population | |
|---|---|
| Total population | 31,653 |
| Population density | 354 / sq mi |
| State FIPS | 24 |
| County FIPS | 021 |
| Geography | |
|---|---|
| Land area | 89.52 sq mi |
| Water area | 0.18 sq mi |
| Latitude | 39.3741 |
| Longitude | -77.1563 |
| Timezone | Eastern (ET) |
| Area code | 240/301 |
Total population by age
Gender
Race & ethnicity
Economics
updated 05/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 14.6% | 22.0% | 28.2% |
| $50k – $100k | 20.5% | 27.2% | 28.2% |
| $100k – $200k | 40.8% | 36.5% | 30.1% |
| Over $200k | 24.1% | 14.3% | 13.4% |
Demographics & statistics
31,653
Population
354
People per sq mi
41.6
Median age
$148,909
Median household income
$55,576
Per capita income
$501,800
Median home value
$1,713
Median monthly rent
92.8%
Home ownership
3.2%
Poverty rate
3.3%
Unemployment
10,237
Housing units
46.0%
Bachelor's or higher
Age distribution
Male
Female
978
Under 5
924
1,317
5–9
1,243
893
10–14
843
1,082
15–19
1,022
927
20–24
875
1,501
25–34
1,417
2,070
35–44
1,955
2,463
45–54
2,325
1,505
55–59
1,421
1,082
60–64
1,022
1,501
65–74
1,418
776
75–84
732
186
85+
175
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 7,534 | 23.8% |
| 18 and over | 24,119 | 76.2% |
| 65 and over | 4,788 | 15.1% |
| Median age | 41.6 years | |
Race & ethnicity
White
83.8%
Two or more races
4.5%
Black or African American
4.1%
Hispanic or Latino
3.8%
Asian
1.9%
Other race
1.8%
American Indian / Alaska Native
0.1%
| Group | Count | % |
|---|---|---|
| White | 27,569 | 83.8% |
| Two or more races | 1,483 | 4.5% |
| Black or African American | 1,350 | 4.1% |
| Hispanic or Latino | 1,245 | 3.8% |
| Asian | 614 | 1.9% |
| Other race | 605 | 1.8% |
| American Indian / Alaska Native | 18 | 0.1% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 14.6% | 22.0% | 28.2% |
| $50k – $100k | 20.5% | 27.2% | 28.2% |
| $100k – $200k | 40.8% | 36.5% | 30.1% |
| Over $200k | 24.1% | 14.3% | 13.4% |
Under $10k
2.3%
$10k–$15k
0.5%
$15k–$25k
2.5%
$25k–$35k
2.9%
$35k–$50k
4.2%
$50k–$75k
8.8%
$75k–$100k
8.1%
$100k–$150k
21.5%
$150k–$200k
19.0%
$200k+
30.3%
| Range | % of households |
|---|---|
| Under $10k | 2.3% |
| $10k–$15k | 0.5% |
| $15k–$25k | 2.5% |
| $25k–$35k | 2.9% |
| $35k–$50k | 4.2% |
| $50k–$75k | 8.8% |
| $75k–$100k | 8.1% |
| $100k–$150k | 21.5% |
| $150k–$200k | 19.0% |
| $200k+ | 30.3% |
| Median income | $148,909 |
Housing
Home values
Under $50k
1.7%
$50k–$100k
0.8%
$100k–$150k
0.2%
$150k–$200k
0.6%
$200k–$300k
6.4%
$300k–$500k
40.0%
$500k–$1M
48.6%
$1M+
1.7%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $501,800 |
| Median rent / month | $1,713 |
| Owner occupied | 92.8% |
| Renter occupied | 7.2% |
| Vacant | 3.9% |
| Single-family detached | 86.0% |
| Large apartment buildings | 0.6% |
| Mobile homes | 2.1% |
| Median rooms | 8.1 |
| Avg household size (owned) | 3.00 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.6% |
| 2010–2019 | 3.7% |
| 2000–2009 | 18.0% |
| 1990–1999 | 22.1% |
| 1980–1989 | 20.5% |
| 1970–1979 | 18.3% |
| 1960–1969 | 5.6% |
| 1950–1959 | 3.0% |
| 1940–1949 | 1.4% |
| 1939 or earlier | 6.8% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 1.0% |
| 1 bedroom | 0.8% |
| 2 bedrooms | 8.4% |
| 3 bedrooms | 35.5% |
| 4 bedrooms | 41.9% |
| 5+ bedrooms | 12.4% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 2.4% |
| 1 vehicle | 13.3% |
| 2 vehicles | 40.3% |
| 3 or more | 44.0% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 24.0% |
| Electricity | 51.1% |
| Propane / LP gas | 4.9% |
| Fuel oil | 14.8% |
| Wood | 2.3% |
| Solar | 0.3% |
| No fuel used | 0.9% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 7,550 | 71.4% |
| Cohabiting couple | 360 | 3.4% |
| Male householder, no spouse | 1,193 | 11.3% |
| Female householder, no spouse | 1,467 | 13.9% |
| Households with children under 18 | 3,589 | 34.0% |
| Households with seniors (65+) | 3,216 | 30.4% |
| Average household size | 2.98 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 27.6% | 22.0% |
| Married | 63.2% | 61.4% |
| Separated | 0.9% | 0.5% |
| Widowed | 2.4% | 6.2% |
| Divorced | 5.9% | 9.9% |
Education
Less than 9th grade
2.3%
Some HS, no diploma
2.8%
HS graduate
22.6%
Some college, no degree
17.3%
Associate's degree
9.0%
Bachelor's degree
26.6%
Graduate / professional
19.4%
| Metric | % |
|---|---|
| HS diploma or higher | 94.9% |
| Bachelor's or higher | 46.0% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 576 | 7.3% |
| Kindergarten | 427 | 5.4% |
| Elementary school | 3,231 | 40.8% |
| High school | 1,578 | 19.9% |
| College / grad school | 2,110 | 26.6% |
Employment
Industry of employment
Education & healthcare
18.8%
Professional & management
18.7%
Public administration
12.0%
Retail trade
9.7%
Construction
9.0%
Arts, food & hospitality
7.7%
Manufacturing
7.3%
Other services
5.0%
Finance & real estate
4.4%
Transportation & utilities
3.3%
Wholesale trade
2.0%
Information
1.2%
Agriculture & mining
0.8%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 50.9% |
| Service | 14.9% |
| Sales & office | 17.8% |
| Natural resources & construction | 7.3% |
| Production & transportation | 9.1% |
Employment type
| Type | % |
|---|---|
| Private sector | 69.5% |
| Government | 23.5% |
| Self-employed | 6.6% |
| Unpaid family workers | 0.4% |
Commute
| Method | % |
|---|---|
| Drive alone | 76.4% |
| Carpool | 6.2% |
| Public transit | 0.4% |
| Walk | 0.6% |
| Work from home | 16.0% |
| Other means | 0.4% |
| Avg commute (minutes) | 36.2 |
Poverty
All people
3.2%
Under 18 years
3.4%
18 and over
3.2%
Married-couple families
1.0%
Female-led households
8.5%
Income support
| Source | % of households |
|---|---|
| Social Security | 27.1% |
| Retirement income | 26.1% |
| Supplemental Security | 1.8% |
| Cash public assistance | 2.2% |
| Food stamps / SNAP | 3.3% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 30.3% |
| High blood pressure | 30.2% |
| High cholesterol | 34.0% |
| Diabetes | 8.3% |
| Heart disease | 4.8% |
| Stroke | 2.2% |
| Asthma | 9.2% |
| Arthritis | 22.3% |
| Kidney disease | 2.3% |
| Pulmonary disease | 4.9% |
| Cancer | 6.6% |
| Behavior / access | % |
|---|---|
| Smoking | 12.4% |
| Binge drinking | 16.8% |
| No physical activity | 17.0% |
| Less than 7 hrs sleep | 29.1% |
| Depression | 18.8% |
| Fair or poor health | 9.1% |
| Poor mental health | 12.9% |
| Poor physical health | 7.3% |
| No health insurance | 7.8% |
| Visited doctor (checkup) | 75.7% |
| Visited dentist | 72.3% |
| Cholesterol screening | 93.2% |
| Teeth loss | 7.5% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 1,843 | 7.7% |
| Disability | % |
|---|---|
| Any disability | 10.0% |
| Under 18 | 4.6% |
| 18–64 years | 7.7% |
| 65 and over | 28.4% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 88.9% |
| Public insurance | 21.2% |
| No insurance | 2.0% |
| Uninsured under 19 | 1.0% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 29,751 | 94.0% |
| Spanish | 953 | 3.2% |
| Other Indo-European | 454 | 1.5% |
| Asian & Pacific Islander | 174 | 0.6% |
| Other languages | 125 | 0.4% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 29,396 | 92.9% |
| Born in same state | 28,978 | 91.5% |
| Born in different state | 17,751 | 56.1% |
| Foreign born | 418 | 1.3% |
| Naturalized citizen | 2,257 | 7.1% |
| Not a US citizen | 1,373 | 60.8% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| Italian | 6,962 | 22% |
| French | 5,190 | 16.4% |
| Arab | 2,049 | 6.5% |
| Polish | 226 | 0.7% |
| Irish | 220 | 0.7% |
| Ancestry | Count | % |
|---|---|---|
| English | 198 | 0.6% |
| Norwegian | 114 | 0.4% |
| German | 113 | 0.4% |
| Dutch | 28 | 0.1% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 33.4% |
| Internet access | 95.6% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 21771
What city is ZIP code 21771 in?
ZIP code 21771 is primarily assigned to Mount Airy, Maryland.
What county is ZIP code 21771 in?
ZIP code 21771 falls within Frederick County, Maryland.
Is ZIP code 21771 mostly owner-occupied?
93% of occupied units in ZIP code 21771 are owner-occupied, well above the national average.
How educated is the population of ZIP code 21771?
46% of residents hold a bachelor's degree or higher — well above the national average of ~33%, reflecting a highly educated population.
What is the median household income in ZIP code 21771?
The median household income in ZIP code 21771 is $148,909, above the national median of ~$75,000.
What is the typical home value in ZIP code 21771?
The median home value in ZIP code 21771 is $501,800.
What timezone is ZIP code 21771 in?
ZIP code 21771 observes the EST timezone.