ZIP codes in Fremont County
11 ZIPs touch Fremont County, Idaho. The blue dashed line is the county border; orange ZIPs reach into it.
11
ZIP codes
6
cross the county line
68,945
people in these ZIPs
44
counties in ID
Most people
Fremont County ZIP list
More counties in Idaho
- Cassia County9
- Clark County4
- Clearwater County7
- Custer County7
- Elmore County9
- Franklin County7
- Gem County7
- Gooding County6
- Idaho County16
- Jefferson County10
- Jerome County5
- Kootenai County15
Questions people actually ask
How many ZIP codes are in Fremont County, Idaho?
11 ZIP codes reach into Fremont County. 6 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Fremont County has the most people?
83440 (Rexburg) has about 51,421 residents, the most of any ZIP touching Fremont County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Fremont County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Fremont County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
Keep exploring
Updated 2026-11-10 · Where the data comes from