ZIP codes in Isabella County
17 ZIPs touch Isabella County, Michigan. The blue dashed line is the county border; orange ZIPs reach into it.
17
ZIP codes
12
cross the county line
108,952
people in these ZIPs
83
counties in MI
Most people
Isabella County ZIP list
More counties in Michigan
- Houghton County20
- Huron County18
- Ingham County39
- Ionia County22
- Iosco County13
- Iron County9
- Jackson County30
- Kalamazoo County31
- Kalkaska County8
- Kent County60
- Keweenaw County6
- Lake County11
Questions people actually ask
How many ZIP codes are in Isabella County, Michigan?
17 ZIP codes reach into Isabella County, including 1 PO Box or single-address ZIPs placed by the town they serve. 12 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Isabella County has the most people?
48858 (Mount Pleasant) has about 42,226 residents, the most of any ZIP touching Isabella County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Isabella 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 Isabella 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