ZIP codes in Piatt County
16 ZIPs touch Piatt County, Illinois. The blue dashed line is the county border; orange ZIPs reach into it.
16
ZIP codes
11
cross the county line
36,688
people in these ZIPs
102
counties in IL
Most people
Piatt County ZIP list
More counties in Illinois
- Montgomery County28
- Morgan County17
- Moultrie County11
- Ogle County27
- Peoria County49
- Perry County12
- Pike County16
- Pope County10
- Pulaski County10
- Putnam County8
- Randolph County18
- Richland County9
Questions people actually ask
How many ZIP codes are in Piatt County, Illinois?
16 ZIP codes reach into Piatt County. 11 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Piatt County has the most people?
61853 (Mahomet) has about 14,831 residents, the most of any ZIP touching Piatt County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Piatt 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 Piatt 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