ZIP codes in Ionia County
22 ZIPs touch Ionia County, Michigan. The blue dashed line is the county border; orange ZIPs reach into it.
22
ZIP codes
15
cross the county line
142,315
people in these ZIPs
83
counties in MI
Most people
Ionia County ZIP list
More counties in Michigan
- Grand Traverse County13
- Gratiot County23
- Hillsdale County22
- Houghton County20
- Huron County18
- Ingham County39
- Iosco County13
- Iron County9
- Isabella County17
- Jackson County30
- Kalamazoo County31
- Kalkaska County8
Questions people actually ask
How many ZIP codes are in Ionia County, Michigan?
22 ZIP codes reach into Ionia County, including 1 PO Box or single-address ZIPs placed by the town they serve. 15 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Ionia County has the most people?
48846 (Ionia) has about 21,613 residents, the most of any ZIP touching Ionia County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Ionia 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 Ionia 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