ZIP codes in Montgomery County
11 ZIPs touch Montgomery County, Iowa. The blue dashed line is the county border; orange ZIPs reach into it.
11
ZIP codes
8
cross the county line
13,280
people in these ZIPs
99
counties in IA
Most people
Montgomery County ZIP list
More counties in Iowa
- Marion County19
- Marshall County21
- Mills County11
- Mitchell County13
- Monona County15
- Monroe County7
- Muscatine County14
- O'Brien County14
- Osceola County8
- Page County14
- Palo Alto County14
- Plymouth County15
Questions people actually ask
How many ZIP codes are in Montgomery County, Iowa?
11 ZIP codes reach into Montgomery County, including 1 PO Box or single-address ZIPs placed by the town they serve. 8 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Montgomery County has the most people?
51566 (Red Oak) has about 7,010 residents, the most of any ZIP touching Montgomery County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Montgomery 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 Montgomery 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