20818 ZIP Code — Cabin John, MD

Montgomery County, Maryland

ZIP code 20818 is located in Cabin John, Maryland, within Montgomery County. It covers approximately 0.93 square miles and serves a population of 1,787 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 240/301.

About ZIP code 20818

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1980s, giving the area an established character. Median home value is $1,093,600. Owner-occupancy is high at 96%, well above the national average.

The gap between median ($211,196) and mean household income suggests income inequality — a small number of higher earners pull the average up. 42% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 32 minutes is near the national average. Remote work is prevalent — 33% of workers work from home.

Educational attainment is high — 93% of residents hold a bachelor's degree or higher, well above the national average of 33%.

Overall, ZIP code 20818 reflects a community defined by a highly educated population, high homeownership, a high rate of remote workers, and a significant Social Security-dependent population.

1,787

population

0.93

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

20818 ZIP code map

Cities in ZIP code 20818

Below are the cities the US Postal Service accepts for ZIP code 20818. Using any city not on this list may result in mail delivery delays.

City	Status
Cabin John	Preferred

Nearby ZIP codes

20812 Glen Echo (1.3 mi) 20817 Bethesda (1.8 mi) 20816 Bethesda (2.2 mi) 22101 Mc Lean (2.8 mi) 22109 Mc Lean (3.2 mi) 22107 Mc Lean (3.2 mi) 22108 Mc Lean (3.2 mi) 20811 Bethesda (3.3 mi) 20810 Bethesda (3.3 mi) 20894 Bethesda (3.4 mi) 20889 Bethesda (3.4 mi) 20892 Bethesda (3.5 mi)

Demographics updated 05/2026

Population
Total population	1,787
Population density	1,922 / sq mi
State FIPS	24
County FIPS	031

Geography
Land area	0.93 sq mi
Water area	0.42 sq mi
Latitude	38.9770
Longitude	-77.1628
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	7.2%	20.6%	28.2%
$50k – $100k	16.7%	24.2%	28.2%
$100k – $200k	33.5%	31.9%	30.1%
Over $200k	42.7%	23.3%	13.4%

Demographics & statistics

1,787

Population

1,922

People per sq mi

50.5

Median age

$211,196

Median household income

$132,988

Per capita income

$1,093,600

Median home value

Median monthly rent

95.6%

Home ownership

0.1%

Poverty rate

0.0%

Unemployment

729

Housing units

93.4%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

125

10–14

15–19

20–24

25–34

35–44

134

45–54

143

55–59

60–64

102

103

65–74

148

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	391	21.9%
18 and over	1,396	78.1%
65 and over	454	25.4%
Median age	50.5 years

Race & ethnicity

White 53.1%

Hispanic or Latino 13.8%

Asian 12.2%

Two or more races 11.5%

Other race 4.7%

Black or African American 4.5%

American Indian / Alaska Native 0.1%

Group	Count	%
White	1,102	53.1%
Hispanic or Latino	287	13.8%
Asian	254	12.2%
Two or more races	238	11.5%
Other race	97	4.7%
Black or African American	94	4.5%
American Indian / Alaska Native	2	0.1%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	7.2%	20.6%	28.2%
$50k – $100k	16.7%	24.2%	28.2%
$100k – $200k	33.5%	31.9%	30.1%
Over $200k	42.7%	23.3%	13.4%

$15k–$25k 2.5%

$25k–$35k 2.4%

$35k–$50k 11.4%

$50k–$75k 4.8%

$75k–$100k 5.6%

$100k–$150k 2.5%

$150k–$200k 10.2%

$200k+ 60.5%

Range	% of households
$15k–$25k	2.5%
$25k–$35k	2.4%
$35k–$50k	11.4%
$50k–$75k	4.8%
$75k–$100k	5.6%
$100k–$150k	2.5%
$150k–$200k	10.2%
$200k+	60.5%
Median income	$211,196

Housing

Home values

$100k–$150k 1.2%

$200k–$300k 2.7%

$300k–$500k 2.7%

$500k–$1M 33.4%

$1M+ 60.1%

Housing overview

Metric	Value
Median home value	$1,093,600
Median rent / month	$0
Owner occupied	95.6%
Renter occupied	4.4%
Vacant	6.8%
Single-family detached	91.1%
Large apartment buildings	2.4%
Mobile homes	0.0%
Median rooms	8.5
Avg household size (owned)	2.48

Year built

Era	%
2020 or later	0.0%
2010–2019	18.0%
2000–2009	3.2%
1990–1999	3.4%
1980–1989	23.2%
1970–1979	9.6%
1960–1969	13.2%
1950–1959	15.7%
1940–1949	6.8%
1939 or earlier	7.0%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	2.4%
2 bedrooms	17.4%
3 bedrooms	27.2%
4 bedrooms	27.8%
5+ bedrooms	25.3%

Vehicles per household

Vehicles	% of households
No vehicle	2.4%
1 vehicle	28.1%
2 vehicles	48.2%
3 or more	21.3%

Heating fuel

Fuel type	%
Utility gas	35.6%
Electricity	39.4%
Propane / LP gas	9.3%
Fuel oil	15.7%

Households & families

Household type	Count	%
Married-couple family	433	61.2%
Cohabiting couple	18	2.5%
Male householder, no spouse	29	4.1%
Female householder, no spouse	228	32.2%
Households with children under 18	209	29.5%
Households with seniors (65+)	358	50.6%
Average household size	2.52

Marital status

Status	Male	Female
Never married	17.2%	23.2%
Married	77.8%	54.5%
Separated	0.0%	1.1%
Widowed	0.0%	4.2%
Divorced	4.9%	16.9%

Education

Less than 9th grade 0.2%

Some HS, no diploma 0.0%

HS graduate 5.0%

Some college, no degree 1.5%

Associate's degree 0.0%

Bachelor's degree 27.2%

Graduate / professional 66.2%

Metric	%
HS diploma or higher	99.8%
Bachelor's or higher	93.4%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	46	8.4%
Kindergarten	40	7.3%
Elementary school	226	41.5%
High school	97	17.8%
College / grad school	136	25.0%

Employment

Industry of employment

Education & healthcare 28.8%

Professional & management 25.3%

Finance & real estate 14.8%

Public administration 13.7%

Other services 5.5%

Retail trade 3.7%

Transportation & utilities 1.9%

Manufacturing 1.8%

Information 1.6%

Construction 1.5%

Arts, food & hospitality 1.4%

Occupation

Category	%
Management, business & arts	86.8%
Service	7.6%
Sales & office	3.7%
Natural resources & construction	0.0%
Production & transportation	1.9%

Employment type

Type	%
Private sector	66.7%
Government	24.2%
Self-employed	9.0%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	61.5%
Carpool	2.7%
Public transit	2.9%
Walk	0.0%
Work from home	32.9%
Other means	0.0%
Avg commute (minutes)	31.7

Poverty

All people 0.1%

Under 18 years 0.0%

18 and over 0.1%

Married-couple families 0.0%

Female-led households 0.0%

Income support

Source	% of households
Social Security	41.7%
Retirement income	32.9%
Supplemental Security	2.5%
Cash public assistance	0.0%
Food stamps / SNAP	0.0%

Health indicators

Condition	%
Obesity	18.5%
High blood pressure	27.6%
High cholesterol	36.8%
Diabetes	7.0%
Heart disease	4.6%
Stroke	1.9%
Asthma	7.5%
Arthritis	19.8%
Kidney disease	2.2%
Pulmonary disease	3.3%
Cancer	7.5%

Behavior / access	%
Smoking	5.4%
Binge drinking	12.5%
No physical activity	10.9%
Less than 7 hrs sleep	24.9%
Depression	14.9%
Fair or poor health	6.0%
Poor mental health	9.0%
Poor physical health	5.2%
No health insurance	5.3%
Visited doctor (checkup)	75.1%
Visited dentist	80.3%
Cholesterol screening	96.2%
Teeth loss	3.3%

Veterans & disability

Veterans	Count	%
Civilian veterans	48	3.5%

Disability	%
Any disability	3.8%
Under 18	0.0%
18–64 years	0.9%
65 and over	13.0%

Health insurance coverage

Type	%
Private insurance	84.8%
Public insurance	32.2%
No insurance	1.5%
Uninsured under 19	0.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	1,747	97.8%
Spanish	10	0.6%
Other Indo-European	2	0.1%
Asian & Pacific Islander	0	0.0%
Other languages	8	0.5%

Place of birth & citizenship

Origin	Count	%
Native born (US)	1,409	78.8%
Born in same state	1,409	78.8%
Born in different state	294	16.5%
Foreign born	0	0.0%
Naturalized citizen	378	21.2%
Not a US citizen	311	82.3%

Ancestry

Ancestry	Count	%
Italian	313	17.5%
French	210	11.8%
Irish	59	3.3%

Ancestry	Count	%
Norwegian	25	1.4%
English	12	0.7%

Technology access

Metric	% of households
Computer access	39.6%
Internet access	100.0%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 20818

What city is ZIP code 20818 in?

ZIP code 20818 is primarily assigned to Cabin John, Maryland.

What county is ZIP code 20818 in?

ZIP code 20818 falls within Montgomery County, Maryland.

How educated is the population of ZIP code 20818?

93% of residents hold a bachelor's degree or higher — well above the national average of ~33%, reflecting a highly educated population.

Is ZIP code 20818 mostly owner-occupied?

96% of occupied units in ZIP code 20818 are owner-occupied, well above the national average.

Does ZIP code 20818 have an older population?

25% of residents in ZIP code 20818 are 65 or older, above the national average of ~17%.

Does ZIP code 20818 have a large retiree population?

42% of households in ZIP code 20818 receive Social Security income, suggesting a significant retiree or disability population.

What timezone is ZIP code 20818 in?

ZIP code 20818 observes the EST timezone.