ZIP codes in Winnebago County
11 ZIPs touch Winnebago County, Iowa. The blue dashed line is the county border; orange ZIPs reach into it.
11
ZIP codes
7
cross the county line
16,588
people in these ZIPs
99
counties in IA
Most people
Winnebago County ZIP list
More counties in Iowa
- Van Buren County13
- Wapello County12
- Warren County21
- Washington County13
- Wayne County13
- Webster County22
- Winneshiek County12
- Woodbury County27
- Worth County10
- Wright County17
Questions people actually ask
How many ZIP codes are in Winnebago County, Iowa?
11 ZIP codes reach into Winnebago County. 7 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Winnebago County has the most people?
50436 (Forest City) has about 5,771 residents, the most of any ZIP touching Winnebago County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Winnebago 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 Winnebago 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.
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Updated 2026-11-10 · Where the data comes from