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 — STATE/ID/COUNTY/FREMONT

Fremont County, ID ZIP codes

Fremont County, ID has 6 ZIP codes, in 6 towns: 83445, 83420, 83429, 83421, 83433 and 83438.

The county seat is St. Anthony.

ZIP codes
6
Towns
6
County seat
St. Anthony
County FIPS
16043
State
Idaho
Population
13,943
Median household income
$72,683
Land area
1,864 sq mi
Metro area
Rexburg

Fremont County ZIP codes by town

St. Anthony (county seat)
83445

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

Map of Fremont County ZIP codes

834208342183429834338343883445

The ZIP codes of Fremont County, 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.

Fremont County in numbers

About 13,943 people live in Fremont County, in 4,654 households, the 23rd most populous of Idaho's 44 counties. The median household income is $72,683 a year, 7% below the Idaho median of $77,800 (US: $80,734). The median owner-occupied home is valued at $314,200 (25% below the Idaho median), and median gross rent is $864 a month. The median age is 40.0; 22.8% of adults 25 and over hold a bachelor's degree or higher (31.8% across Idaho); the average commute takes 24 minutes.

Population13,943Fremont13,943
Households4,654Fremont4,654
Median age40.0Fremont40.0Idaho37.3US 38.9
Median household income$72,683Fremont$72,683Idaho$77,800US $80,734
Median home value$314,200Fremont$314,200Idaho$418,600US $332,700
Median gross rent$864Fremont$864Idaho$1,238US $1,413
Bachelor's degree or higher22.8%Fremont22.8%Idaho31.8%US 35.7%
Mean commute24.1 minFremont24.1 minIdaho21.6 minUS 26.4 min
Population density7 / sq miFremont7 / sq mi

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

Largest towns in Fremont County

Largest towns in Fremont County
TownZIP codesPopulation
St. Anthony 1 3,911
Ashton 1 1,417
Parker 1 607
Chester 1 220
Island Park 1 170
Macks Inn 1 36

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Fremont County.

Not sure you are in Fremont County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Fremont County, with figures

ZIP codes in Fremont County
ZIP City Type Population Median income Median home
83420 Ashton , ID Standard 2,580 $69,286 $337,700
83421 Chester , ID Standard 220 — $282,400
83429 Island Park , ID Standard 628 $78,565 $502,200
83433 Macks Inn , ID Standard 36 $94,250 $265,000
83438 Parker , ID Standard 327 $145,714 $232,800
83445 Saint Anthony , ID Standard 7,975 $68,012 $283,800

Cite this page

zipcodes.pro. “Fremont County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/id/county/fremont

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