ZIP codes in Iowa County
22 ZIPs touch Iowa County, Iowa. The blue dashed line is the county border; orange ZIPs reach into it.
22
ZIP codes
14
cross the county line
27,667
people in these ZIPs
99
counties in IA
Most people
Iowa County ZIP list
More counties in Iowa
- Hardin County15
- Harrison County15
- Henry County12
- Howard County9
- Humboldt County17
- Ida County12
- Jackson County16
- Jasper County21
- Jefferson County17
- Johnson County26
- Jones County17
- Keokuk County21
Questions people actually ask
How many ZIP codes are in Iowa County, Iowa?
22 ZIP codes reach into Iowa County, including 1 PO Box or single-address ZIPs placed by the town they serve. 14 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Iowa County has the most people?
52361 (Williamsburg) has about 4,582 residents, the most of any ZIP touching Iowa County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Iowa 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 Iowa 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