20879 ZIP Code — Gaithersburg, MD
Montgomery County, Maryland
ZIP code 20879 is located in Gaithersburg, Maryland, within Montgomery County. It covers approximately 8.62 square miles and serves a population of 27,489 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 301/240.
About ZIP code 20879
The housing stock consists of a mix of housing types. Most homes were built in the 1980s, giving the area an established character. Median home value is $414,700. Owner-occupancy sits near the national average at 71%.
The gap between median ($100,324) and mean household income suggests income inequality — a small number of higher earners pull the average up.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 33 minutes is near the national average.
Educational attainment is near the national average, with 42% of residents holding a bachelor's degree or higher.
Notable community characteristics include Spanish spoken in 22% of households.
27,489
population
8.62
sq mi land
Standard
ZIP type
Eastern (ET)
timezone
20879 ZIP code map
Cities in ZIP code 20879
Below are the cities the US Postal Service accepts for ZIP code 20879. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Gaithersburg | Acceptable |
| Gaithersburg | Preferred |
Nearby ZIP codes
20886 Montgomery Village (0.2 mi)
20899 Gaithersburg (2.5 mi)
20877 Gaithersburg (2.6 mi)
20855 Derwood (3.4 mi)
20876 Germantown (3.7 mi)
20882 Gaithersburg (4.2 mi)
20878 Gaithersburg (5.6 mi)
20850 Rockville (6 mi)
20874 Germantown (6.2 mi)
20832 Olney (6.2 mi)
20853 Rockville (6.6 mi)
20857 Rockville (6.6 mi)
Demographics
updated 05/2026
| Population | |
|---|---|
| Total population | 27,489 |
| Population density | 3,189 / sq mi |
| State FIPS | 24 |
| County FIPS | 031 |
| Geography | |
|---|---|
| Land area | 8.62 sq mi |
| Water area | 0.04 sq mi |
| Latitude | 39.1764 |
| Longitude | -77.1832 |
| Timezone | Eastern (ET) |
| Area code | 301/240 |
Total population by age
Gender
Race & ethnicity
Economics
updated 05/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 20.0% | 20.6% | 28.2% |
| $50k – $100k | 33.8% | 24.2% | 28.2% |
| $100k – $200k | 33.0% | 31.9% | 30.1% |
| Over $200k | 13.1% | 23.3% | 13.4% |
Demographics & statistics
27,489
Population
3,189
People per sq mi
36.1
Median age
$100,324
Median household income
$41,619
Per capita income
$414,700
Median home value
$1,832
Median monthly rent
71.4%
Home ownership
10.6%
Poverty rate
6.5%
Unemployment
6,671
Housing units
41.7%
Bachelor's or higher
Age distribution
Male
Female
754
Under 5
921
885
5–9
1,083
829
10–14
1,013
759
15–19
927
871
20–24
1,065
1,861
25–34
2,275
1,578
35–44
1,930
1,448
45–54
1,770
950
55–59
1,161
909
60–64
1,112
1,010
65–74
1,235
457
75–84
558
58
85+
70
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 6,297 | 22.9% |
| 18 and over | 21,192 | 77.1% |
| 65 and over | 3,388 | 12.3% |
| Median age | 36.1 years | |
Race & ethnicity
White
29.7%
Hispanic or Latino
19.4%
Black or African American
16.5%
Other race
15.5%
Asian
11.2%
Two or more races
7.2%
American Indian / Alaska Native
0.5%
Native Hawaiian / Pacific Islander
0.1%
| Group | Count | % |
|---|---|---|
| White | 10,120 | 29.7% |
| Hispanic or Latino | 6,620 | 19.4% |
| Black or African American | 5,612 | 16.5% |
| Other race | 5,275 | 15.5% |
| Asian | 3,807 | 11.2% |
| Two or more races | 2,464 | 7.2% |
| American Indian / Alaska Native | 174 | 0.5% |
| Native Hawaiian / Pacific Islander | 37 | 0.1% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 20.0% | 20.6% | 28.2% |
| $50k – $100k | 33.8% | 24.2% | 28.2% |
| $100k – $200k | 33.0% | 31.9% | 30.1% |
| Over $200k | 13.1% | 23.3% | 13.4% |
Under $10k
3.5%
$10k–$15k
1.6%
$15k–$25k
5.5%
$25k–$35k
4.7%
$35k–$50k
5.6%
$50k–$75k
14.2%
$75k–$100k
14.7%
$100k–$150k
19.8%
$150k–$200k
14.1%
$200k+
16.3%
| Range | % of households |
|---|---|
| Under $10k | 3.5% |
| $10k–$15k | 1.6% |
| $15k–$25k | 5.5% |
| $25k–$35k | 4.7% |
| $35k–$50k | 5.6% |
| $50k–$75k | 14.2% |
| $75k–$100k | 14.7% |
| $100k–$150k | 19.8% |
| $150k–$200k | 14.1% |
| $200k+ | 16.3% |
| Median income | $100,324 |
Housing
Home values
Under $50k
3.1%
$50k–$100k
0.8%
$100k–$150k
2.6%
$150k–$200k
5.1%
$200k–$300k
10.7%
$300k–$500k
44.8%
$500k–$1M
30.3%
$1M+
2.6%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $414,700 |
| Median rent / month | $1,832 |
| Owner occupied | 71.4% |
| Renter occupied | 28.6% |
| Vacant | 2.8% |
| Single-family detached | 38.8% |
| Large apartment buildings | 6.6% |
| Mobile homes | 1.2% |
| Median rooms | 6.2 |
| Avg household size (owned) | 3.15 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.1% |
| 2010–2019 | 5.0% |
| 2000–2009 | 9.3% |
| 1990–1999 | 11.9% |
| 1980–1989 | 48.0% |
| 1970–1979 | 21.0% |
| 1960–1969 | 3.4% |
| 1950–1959 | 0.8% |
| 1940–1949 | 0.1% |
| 1939 or earlier | 0.5% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 3.1% |
| 1 bedroom | 11.9% |
| 2 bedrooms | 15.4% |
| 3 bedrooms | 35.8% |
| 4 bedrooms | 23.6% |
| 5+ bedrooms | 10.1% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 5.8% |
| 1 vehicle | 31.6% |
| 2 vehicles | 40.9% |
| 3 or more | 21.7% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 31.7% |
| Electricity | 64.8% |
| Propane / LP gas | 1.6% |
| Fuel oil | 0.7% |
| Solar | 0.3% |
| No fuel used | 0.8% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 4,872 | 54.2% |
| Cohabiting couple | 473 | 5.3% |
| Male householder, no spouse | 1,122 | 12.5% |
| Female householder, no spouse | 2,518 | 28.0% |
| Households with children under 18 | 2,929 | 32.6% |
| Households with seniors (65+) | 2,328 | 25.9% |
| Average household size | 3.05 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 35.1% | 36.8% |
| Married | 58.3% | 46.5% |
| Separated | 0.3% | 1.3% |
| Widowed | 0.9% | 5.2% |
| Divorced | 5.3% | 10.2% |
Education
Less than 9th grade
6.0%
Some HS, no diploma
5.0%
HS graduate
20.0%
Some college, no degree
17.9%
Associate's degree
9.4%
Bachelor's degree
24.6%
Graduate / professional
17.1%
| Metric | % |
|---|---|
| HS diploma or higher | 89.0% |
| Bachelor's or higher | 41.7% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 326 | 4.4% |
| Kindergarten | 336 | 4.6% |
| Elementary school | 3,239 | 44.2% |
| High school | 1,272 | 17.4% |
| College / grad school | 2,156 | 29.4% |
Employment
Industry of employment
Education & healthcare
22.6%
Professional & management
20.2%
Arts, food & hospitality
11.1%
Public administration
9.1%
Retail trade
8.9%
Other services
7.1%
Construction
6.5%
Finance & real estate
4.9%
Manufacturing
3.5%
Transportation & utilities
3.0%
Wholesale trade
1.9%
Information
1.0%
Agriculture & mining
0.3%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 46.4% |
| Service | 19.1% |
| Sales & office | 18.4% |
| Natural resources & construction | 7.3% |
| Production & transportation | 8.8% |
Employment type
| Type | % |
|---|---|
| Private sector | 73.1% |
| Government | 18.2% |
| Self-employed | 8.3% |
| Unpaid family workers | 0.3% |
Commute
| Method | % |
|---|---|
| Drive alone | 68.4% |
| Carpool | 9.6% |
| Public transit | 8.0% |
| Walk | 0.8% |
| Work from home | 12.0% |
| Other means | 1.3% |
| Avg commute (minutes) | 33.3 |
Poverty
All people
10.6%
Under 18 years
11.9%
18 and over
10.3%
Married-couple families
5.9%
Female-led households
8.5%
Income support
| Source | % of households |
|---|---|
| Social Security | 18.4% |
| Retirement income | 18.6% |
| Supplemental Security | 8.5% |
| Cash public assistance | 1.8% |
| Food stamps / SNAP | 10.3% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 22.8% |
| High blood pressure | 25.4% |
| High cholesterol | 30.0% |
| Diabetes | 7.8% |
| Heart disease | 3.7% |
| Stroke | 2.0% |
| Asthma | 8.5% |
| Arthritis | 15.6% |
| Kidney disease | 2.0% |
| Pulmonary disease | 3.7% |
| Cancer | 4.2% |
| Behavior / access | % |
|---|---|
| Smoking | 10.7% |
| Binge drinking | 13.5% |
| No physical activity | 18.3% |
| Less than 7 hrs sleep | 32.2% |
| Depression | 15.9% |
| Fair or poor health | 9.9% |
| Poor mental health | 12.5% |
| Poor physical health | 6.5% |
| No health insurance | 13.9% |
| Visited doctor (checkup) | 70.9% |
| Visited dentist | 65.7% |
| Cholesterol screening | 91.6% |
| Teeth loss | 7.6% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 879 | 4.2% |
| Disability | % |
|---|---|
| Any disability | 9.7% |
| Under 18 | 3.4% |
| 18–64 years | 7.4% |
| 65 and over | 33.8% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 69.7% |
| Public insurance | 31.4% |
| No insurance | 9.6% |
| Uninsured under 19 | 3.8% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 25,814 | 93.9% |
| Spanish | 5,588 | 21.6% |
| Other Indo-European | 3,236 | 12.5% |
| Asian & Pacific Islander | 1,325 | 5.1% |
| Other languages | 752 | 2.9% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 17,284 | 62.9% |
| Born in same state | 16,911 | 61.5% |
| Born in different state | 9,164 | 33.3% |
| Foreign born | 373 | 1.4% |
| Naturalized citizen | 10,205 | 37.1% |
| Not a US citizen | 6,173 | 60.5% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| French | 1,401 | 5.1% |
| Italian | 1,093 | 4% |
| Arab | 765 | 2.8% |
| English | 144 | 0.5% |
| Polish | 113 | 0.4% |
| Ancestry | Count | % |
|---|---|---|
| German | 88 | 0.3% |
| Irish | 54 | 0.2% |
| Norwegian | 33 | 0.1% |
| Dutch | 19 | 0.1% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 32.7% |
| Internet access | 97.6% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 20879
What city is ZIP code 20879 in?
ZIP code 20879 is primarily assigned to Gaithersburg, Maryland.
What county is ZIP code 20879 in?
ZIP code 20879 falls within Montgomery County, Maryland.
Is Spanish widely spoken in ZIP code 20879?
Approximately 22% of households in ZIP code 20879 speak Spanish as a primary language.
What is the typical home value in ZIP code 20879?
The median home value in ZIP code 20879 is $414,700.
What is the population of ZIP code 20879?
ZIP code 20879 has an estimated population of 27,489 residents, with a density of 3,190 people per square mile.
What is the median household income in ZIP code 20879?
The median household income in ZIP code 20879 is $100,324, above the national median of ~$75,000.
What timezone is ZIP code 20879 in?
ZIP code 20879 observes the EST timezone.