County ZIP codes · Iowa · FIPS 19005
Allamakee County, IA ZIP Codes
Allamakee County, Iowa has 10 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 8 of the residential ones lie mainly in Allamakee County and 2 mainly in a neighboring county; 6 cross the county line. Median household income ranges from $64,125 in 52162 (Postville) to $74,259 in 52159 (Monona) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Allamakee County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $68,875 and $73,484.
They carry 10 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 10 residential ZIP codes in Allamakee County
8 ZIP codes lie mainly in Allamakee County; 2 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 52172 | Waukon | 5,877 | 37 | $69k | $166k | 95% |
| 52162 | Postville | 3,744 | 39 | $64k | $133k | 60% |
| 52159 | Monona | 2,398 | 33 | $74k | $165k | 51% |
| 52151 | Lansing | 1,886 | 16 | $70k | $178k | 100% |
| 52160 | New Albin | 818 | 18 | $85k | $211k | 100% |
| 52146 | Harpers Ferry | 752 | 9 | $62k | $235k | 100% |
| 52140 | Dorchester | 671 | 9 | $72k | $208k | 91% |
| 52170 | Waterville | 555 | 11 | $73k | $223k | 100% |
Partly in Allamakee County
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
6 ZIP codes of Allamakee County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Allamakee | Elsewhere |
|---|---|---|
| 52101 | 3% | Winneshiek County97% |
| 52172 | 95% | Winneshiek County5% |
| 52162 | 60% | Clayton County27%; Winneshiek County10%; Fayette County3% |
| 52159 | 51% | Clayton County49% |
| 52156 | 27% | Clayton County73% |
| 52140 | 91% | Winneshiek County9% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
Which first three digits do Allamakee County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Allamakee County starts with 521.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 521 | Waterloo, IA (SCF 506) | 10 | 33 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.