98040 ZIP Code — Mercer Island, WA

King County, Washington

ZIP code 98040 is located in Mercer Island, Washington, within King County. It covers approximately 6.38 square miles and serves a population of 25,464 residents. This is a standard ZIP code in the Pacific (PT) timezone, served by area code 206.

About ZIP code 98040

The housing stock consists of a significant share of large multi-unit buildings. Most homes were built in the 1960s, giving the area an established character. Median home value is $1,683,600. Owner-occupancy sits near the national average at 68%.

The gap between median ($190,985) and mean household income suggests income inequality — a small number of higher earners pull the average up. The poverty rate of 5% is below the national average.

The dominant occupation class is management, business, and professional, with professional and management as the leading industry. The average commute of 27 minutes is near the national average. Remote work is prevalent — 30% of workers work from home.

Educational attainment is high — 78% of residents hold a bachelor's degree or higher, well above the national average of 33%.

Overall, ZIP code 98040 reflects a community defined by a highly educated population and a high rate of remote workers.

25,464

population

6.38

sq mi land

Standard

ZIP type

Pacific (PT)

timezone

98040 ZIP code map

Cities in ZIP code 98040

Below are the cities the US Postal Service accepts for ZIP code 98040. Using any city not on this list may result in mail delivery delays.

City	Status
Mercer Island	Preferred

Nearby ZIP codes

98118 Seattle (2.3 mi) 98144 Seattle (3 mi) 98004 Bellevue (3.8 mi) 98006 Bellevue (3.9 mi) 98108 Seattle (4.1 mi) 98056 Renton (4.3 mi) 98039 Medina (4.3 mi) 98122 Seattle (4.5 mi) 98005 Bellevue (4.7 mi) 98178 Seattle (4.8 mi) 98134 Seattle (4.9 mi) 98104 Seattle (5.1 mi)

Demographics updated 05/2026

Population
Total population	25,464
Population density	3,991 / sq mi
State FIPS	53
County FIPS	033

Geography
Land area	6.38 sq mi
Water area	6.52 sq mi
Latitude	47.5652
Longitude	-122.2331
Timezone	Pacific (PT)
Area code	206

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	18.7%	24.4%	31.7%
$50k – $100k	15.6%	25.9%	30.6%
$100k – $200k	24.4%	30.8%	27.1%
Over $200k	41.4%	18.9%	10.6%

Demographics & statistics

25,464

Population

3,991

People per sq mi

45.3

Median age

$190,985

Median household income

$113,575

Per capita income

$1,683,600

Median home value

$2,315

Median monthly rent

68.0%

Home ownership

5.3%

Poverty rate

2.6%

Unemployment

7,381

Housing units

77.7%

Bachelor's or higher

Age distribution

Male Female

486

Under 5

544

784

5–9

879

911

10–14

1,022

899

15–19

1,007

379

20–24

424

999

25–34

1,119

1,470

35–44

1,647

2,035

45–54

2,281

864

55–59

968

727

60–64

814

1,227

65–74

1,375

731

75–84

819

496

85+

557

← Male

Female →

Age summary

Group	Count	%
Under 18	5,882	23.1%
18 and over	19,582	76.9%
65 and over	5,205	20.4%
Median age	45.3 years

Race & ethnicity

White 64.3%

Asian 21.6%

Two or more races 8.6%

Hispanic or Latino 3%

Black or African American 1.3%

Other race 1.1%

American Indian / Alaska Native 0.1%

Group	Count	%
White	16,882	64.3%
Asian	5,658	21.6%
Two or more races	2,264	8.6%
Hispanic or Latino	778	3%
Black or African American	340	1.3%
Other race	296	1.1%
American Indian / Alaska Native	24	0.1%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	18.7%	24.4%	31.7%
$50k – $100k	15.6%	25.9%	30.6%
$100k – $200k	24.4%	30.8%	27.1%
Over $200k	41.4%	18.9%	10.6%

Under $10k 2.9%

$10k–$15k 0.6%

$15k–$25k 2.9%

$25k–$35k 5.2%

$35k–$50k 4.5%

$50k–$75k 9.0%

$75k–$100k 5.6%

$100k–$150k 12.3%

$150k–$200k 8.7%

$200k+ 48.3%

Range	% of households
Under $10k	2.9%
$10k–$15k	0.6%
$15k–$25k	2.9%
$25k–$35k	5.2%
$35k–$50k	4.5%
$50k–$75k	9.0%
$75k–$100k	5.6%
$100k–$150k	12.3%
$150k–$200k	8.7%
$200k+	48.3%
Median income	$190,985

Housing

Home values

Under $50k 0.7%

$100k–$150k 1.1%

$150k–$200k 0.1%

$200k–$300k 0.8%

$300k–$500k 4.5%

$500k–$1M 7.9%

$1M+ 84.9%

Housing overview

Metric	Value
Median home value	$1,683,600
Median rent / month	$2,315
Owner occupied	68.0%
Renter occupied	32.0%
Vacant	7.0%
Single-family detached	65.8%
Large apartment buildings	23.5%
Mobile homes	0.5%
Median rooms	6.8
Avg household size (owned)	2.88

Year built

Era	%
2020 or later	0.5%
2010–2019	8.5%
2000–2009	11.7%
1990–1999	7.9%
1980–1989	9.9%
1970–1979	17.8%
1960–1969	22.0%
1950–1959	11.7%
1940–1949	6.6%
1939 or earlier	3.2%

Bedrooms

Size	% of units
No bedroom (studio)	4.8%
1 bedroom	11.9%
2 bedrooms	19.2%
3 bedrooms	19.1%
4 bedrooms	29.0%
5+ bedrooms	16.0%

Vehicles per household

Vehicles	% of households
No vehicle	6.1%
1 vehicle	28.5%
2 vehicles	41.2%
3 or more	24.2%

Heating fuel

Fuel type	%
Utility gas	60.0%
Electricity	36.3%
Propane / LP gas	1.2%
Fuel oil	1.2%
Wood	0.2%
Solar	0.1%
No fuel used	0.7%

Households & families

Household type	Count	%
Married-couple family	6,298	64.4%
Cohabiting couple	389	4.0%
Male householder, no spouse	965	9.9%
Female householder, no spouse	2,130	21.8%
Households with children under 18	3,339	34.1%
Households with seniors (65+)	3,413	34.9%
Average household size	2.59

Marital status

Status	Male	Female
Never married	23.5%	21.0%
Married	68.7%	60.7%
Separated	0.4%	0.5%
Widowed	2.4%	8.9%
Divorced	5.0%	8.9%

Education

Less than 9th grade 1.5%

Some HS, no diploma 0.7%

HS graduate 5.7%

Some college, no degree 8.8%

Associate's degree 5.5%

Bachelor's degree 38.2%

Graduate / professional 39.6%

Metric	%
HS diploma or higher	97.8%
Bachelor's or higher	77.7%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	532	7.7%
Kindergarten	206	3.0%
Elementary school	2,914	42.3%
High school	2,022	29.4%
College / grad school	1,207	17.5%

Employment

Industry of employment

Professional & management 26.8%

Education & healthcare 20.8%

Finance & real estate 10.7%

Retail trade 10.1%

Arts, food & hospitality 6.3%

Information 5.6%

Manufacturing 5.2%

Other services 3.8%

Transportation & utilities 3.1%

Wholesale trade 3.0%

Construction 2.3%

Public administration 2.2%

Occupation

Category	%
Management, business & arts	70.6%
Service	6.9%
Sales & office	19.2%
Natural resources & construction	1.2%
Production & transportation	2.1%

Employment type

Type	%
Private sector	80.5%
Government	9.7%
Self-employed	9.5%
Unpaid family workers	0.2%

Commute

Method	%
Drive alone	52.3%
Carpool	6.4%
Public transit	7.2%
Walk	2.0%
Work from home	30.3%
Other means	1.7%
Avg commute (minutes)	27.0

Poverty

All people 5.3%

Under 18 years 6.0%

18 and over 5.0%

Married-couple families 2.5%

Female-led households 10.7%

Income support

Source	% of households
Social Security	27.8%
Retirement income	24.5%
Supplemental Security	2.2%
Cash public assistance	1.7%
Food stamps / SNAP	1.8%

Health indicators

Condition	%
Obesity	18.6%
High blood pressure	29.9%
High cholesterol	34.0%
Diabetes	7.2%
Heart disease	5.3%
Stroke	2.4%
Asthma	8.3%
Arthritis	22.5%
Kidney disease	2.6%
Pulmonary disease	3.6%
Cancer	8.5%

Behavior / access	%
Smoking	6.4%
Binge drinking	15.5%
No physical activity	11.3%
Less than 7 hrs sleep	23.3%
Depression	20.5%
Fair or poor health	7.9%
Poor mental health	9.9%
Poor physical health	6.9%
No health insurance	5.7%
Visited doctor (checkup)	72.9%
Visited dentist	79.9%
Cholesterol screening	93.7%
Teeth loss	4.6%

Veterans & disability

Veterans	Count	%
Civilian veterans	856	4.4%

Disability	%
Any disability	9.8%
Under 18	5.1%
18–64 years	4.7%
65 and over	29.8%

Health insurance coverage

Type	%
Private insurance	87.8%
Public insurance	23.8%
No insurance	2.1%
Uninsured under 19	3.2%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	24,434	96.0%
Spanish	1,829	7.5%
Other Indo-European	100	0.4%
Asian & Pacific Islander	309	1.3%
Other languages	1,405	5.8%

Place of birth & citizenship

Origin	Count	%
Native born (US)	19,207	75.4%
Born in same state	18,624	73.1%
Born in different state	8,722	34.3%
Foreign born	583	2.3%
Naturalized citizen	6,257	24.6%
Not a US citizen	3,700	59.1%

Ancestry

Ancestry	Count	%
French	3,322	13%
Italian	2,248	8.8%
Polish	1,012	4%
Arab	622	2.4%
German	293	1.2%

Ancestry	Count	%
Dutch	238	0.9%
English	226	0.9%
Irish	171	0.7%
Norwegian	149	0.6%

Technology access

Metric	% of households
Computer access	38.4%
Internet access	97.3%

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

Frequently asked questions about ZIP code 98040

What city is ZIP code 98040 in?

ZIP code 98040 is primarily assigned to Mercer Island, Washington.

What county is ZIP code 98040 in?

ZIP code 98040 falls within King County, Washington.

How educated is the population of ZIP code 98040?

78% 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 98040?

The median household income in ZIP code 98040 is $190,985, above the national median of ~$75,000.

What is the typical home value in ZIP code 98040?

The median home value in ZIP code 98040 is $1,683,600.

What is the population of ZIP code 98040?

ZIP code 98040 has an estimated population of 25,464 residents, with a density of 3,989 people per square mile.

What timezone is ZIP code 98040 in?

ZIP code 98040 observes the PST timezone.