Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — CITY/WA/MERCER-ISLAND

Mercer Island ZIP code, Washington

The ZIP code for Mercer Island, WA is 98040.

USPS city name
1 ZIP code
Population
25,307

Mercer Island in numbers

About 25,307 people live in Mercer Island, in 10,068 households. The median household income is $219,069 a year, 2.2 times the Washington median of $98,141 (US: $80,734). The median owner-occupied home is valued at $2,000,000+, and median gross rent is $2,502 a month. The median age is 46.4; 81.4% of adults 25 and over hold a bachelor's degree or higher (39.6% across Washington); the average commute takes 24 minutes.

Population25,307Mercer Island25,307
Households10,068Mercer Island10,068
Median age46.4Mercer Island46.4Washington38.3US 38.9
Median household income$219,069Mercer Island$219,069Washington$98,141US $80,734
Median home value$2,000,000+Mercer Island$2,000,000+Washington$564,600US $332,700
Median gross rent$2,502Mercer Island$2,502Washington$1,760US $1,413
Bachelor's degree or higher81.4%Mercer Island81.4%Washington39.6%US 35.7%
Mean commute23.6 minMercer Island23.6 minWashington26.6 minUS 26.4 min
Population density3,965 / sq miMercer Island3,965 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, for the census place Mercer Island city. Survey estimates carry margins of error, wider for small places. Sources and methods.

ZIP codes addressed as Mercer Island

ZIP codes with the USPS city name Mercer Island
ZIP City Type Population Median income Median home
98040 Mercer Island , WA Standard 25,307 $219,069 $2,000,000+

Map of Mercer Island ZIP codes

98040

The ZIP codes of Mercer Island, WA, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Towns near Mercer Island

The nearest larger towns are Bellevue (151,847 people, 4.2 mi), Renton (105,317 people, 6.1 mi) and Seattle (754,195 people, 6.8 mi).

Towns near Mercer Island
TownPopulationDistance
Newcastle 12,989 3.8 mi
Bellevue 151,847 4.2 mi
Medina 2,928 4.4 mi
Clyde Hill 3,119 4.6 mi
Bryn Mawr-Skyway 17,638 4.8 mi
Boulevard Park 4,575 5.2 mi
Renton 105,317 6.1 mi
Tukwila 21,451 6.4 mi
White Center 14,886 6.6 mi
Seattle 754,195 6.8 mi
Burien 51,513 8.1 mi
Issaquah 39,591 8.6 mi
SeaTac 32,414 8.9 mi
Fairwood 17,856 9.1 mi

More nearby: every ZIP code in King County · Washington ZIP codes

Cite this page

zipcodes.pro. “Mercer Island, WA ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/city/wa/mercer-island

Underlying data is public domain or openly licensed — sources, vintages and licences.