Iowa ZIP codes
Iowa holds 1,055 ZIP codes between 50001 and 52809. The tables rank the places and counties with the most codes; the guide below decodes the numbering.
Places with the most ZIP codes in Iowa
| Place | ZIP codes |
|---|---|
| Des Moines | 57 |
| Cedar Rapids | 14 |
| Davenport | 9 |
| Sioux City | 9 |
| Iowa City | 6 |
| Dubuque | 5 |
| Ames | 5 |
| Waterloo | 4 |
| Clinton | 4 |
| Boone | 3 |
| Urbandale | 3 |
| Council Bluffs | 3 |
| Cedar Falls | 2 |
| Mason City | 2 |
| Amana | 2 |
| Fairfield | 2 |
| Melcher Dallas | 2 |
| Red Oak | 2 |
| Shenandoah | 2 |
| Ankeny | 2 |
Iowa counties by ZIP count
| County | ZIP codes |
|---|---|
| Polk | 78 |
| Linn | 31 |
| Woodbury | 24 |
| Scott | 22 |
| Pottawattamie | 19 |
| Clinton | 18 |
| Dubuque | 18 |
| Story | 18 |
| Benton | 15 |
| Clayton | 15 |
Reading a Iowa ZIP code
Iowa holds 1,055 ZIP codes between 50001 and 52809, spread over 99 counties. Des Moines leads the state with 57 codes, ahead of Cedar Rapids with 14. Every code here opens with the digit 5: that opening number is the national postal region Iowa belongs to, the next two digits name the sectional center that sorts the mail, and the final two point to the local office. A ZIP+4 suffix narrows delivery to a block face. Boundaries follow carrier routes rather than city limits, which is why Des Moines spreads across 57 codes while some rural codes cross county lines.
Source: GeoNames postal dataset (CC BY 4.0), snapshot of 2026-07-09. Counts cover standard delivery ZIPs listed for Iowa; unique and PO box codes may add to these totals.
Last updated: · Methodology and sources