State · counties
Counties in Iowa
The 99 counties recorded for ZIP codes in Iowa, with the number of ZIP codes, total population, and median income in each. County names come from the site's ZIP records (GeoNames postal data); population is summed across member ZIPs and median income is the equal-weight average of member ZIP medians, the same rollup rule described on the methodology page.
| County | ZIP codes | Population | Median income |
|---|---|---|---|
| Polk | 78 | 533,740 | $87,562 |
| Linn | 31 | 230,416 | $88,839 |
| Scott | 22 | 174,697 | $79,223 |
| Johnson | 14 | 151,000 | $79,026 |
| Black Hawk | 13 | 130,533 | $71,567 |
| Woodbury | 24 | 106,982 | $72,375 |
| Story | 18 | 101,460 | $83,185 |
| Dubuque | 18 | 101,403 | $87,747 |
| Pottawattamie | 19 | 94,010 | $78,702 |
| Dallas | 15 | 61,064 | $90,393 |
| Warren | 13 | 52,593 | $89,930 |
| Clinton | 18 | 45,837 | $67,344 |
| Muscatine | 10 | 43,916 | $76,996 |
| Cerro Gordo | 11 | 42,577 | $63,787 |
| Marshall | 13 | 40,003 | $77,568 |
| Des Moines | 7 | 38,265 | $70,751 |
| Webster | 14 | 36,750 | $68,237 |
| Jasper | 12 | 36,335 | $77,468 |
| Sioux | 13 | 35,809 | $80,482 |
| Wapello | 7 | 35,365 | $58,156 |
| Marion | 12 | 33,930 | $81,731 |
| Lee | 11 | 33,074 | $80,834 |
| Bremer | 8 | 25,720 | $79,129 |
| Benton | 15 | 25,364 | $90,133 |
| Boone | 9 | 24,827 | $71,301 |
| Plymouth | 9 | 24,560 | $84,636 |
| Washington | 8 | 24,479 | $74,807 |
| Buchanan | 11 | 21,937 | $71,445 |
| Carroll | 12 | 21,317 | $65,323 |
| Henry | 10 | 21,171 | $62,658 |
| Buena Vista | 9 | 21,099 | $67,022 |
| Mahaska | 9 | 20,636 | $61,873 |
| Jones | 10 | 20,030 | $69,559 |
| Jackson | 12 | 19,512 | $71,024 |
| Poweshiek | 8 | 19,484 | $68,217 |
| Winneshiek | 8 | 19,305 | $68,754 |
| Fayette | 14 | 18,771 | $61,026 |
| Hardin | 13 | 18,157 | $73,107 |
| Dickinson | 7 | 17,711 | $67,597 |
| Tama | 13 | 17,245 | $68,687 |
| Clayton | 15 | 17,119 | $63,087 |
| Cedar | 8 | 17,022 | $72,111 |
| Delaware | 10 | 16,395 | $74,516 |
| Crawford | 12 | 16,300 | $64,713 |
| Madison | 8 | 16,046 | $82,928 |
| Iowa | 13 | 15,952 | $71,810 |
| Clay | 9 | 15,806 | $73,528 |
| Jefferson | 6 | 15,413 | $57,133 |
| Floyd | 7 | 15,320 | $66,823 |
| Page | 11 | 15,227 | $61,764 |
| Butler | 12 | 14,993 | $65,137 |
| Hamilton | 9 | 14,865 | $67,724 |
| Harrison | 10 | 14,850 | $68,413 |
| O'Brien | 8 | 14,488 | $68,472 |
| Mills | 8 | 14,353 | $76,374 |
| Kossuth | 12 | 14,269 | $59,646 |
| Allamakee | 7 | 14,216 | $63,127 |
| Cass | 8 | 13,932 | $63,792 |
| Wright | 9 | 12,857 | $73,379 |
| Appanoose | 9 | 12,737 | $67,002 |
| Union | 7 | 12,468 | $67,913 |
| Chickasaw | 7 | 12,378 | $65,410 |
| Lyon | 8 | 12,169 | $76,273 |
| Winnebago | 7 | 11,931 | $65,256 |
| Cherokee | 8 | 11,520 | $66,048 |
| Guthrie | 9 | 11,462 | $67,825 |
| Grundy | 9 | 11,393 | $84,011 |
| Howard | 6 | 11,098 | $61,371 |
| Keokuk | 15 | 11,078 | $59,867 |
| Shelby | 9 | 10,453 | $78,640 |
| Montgomery | 6 | 10,357 | $59,630 |
| Calhoun | 10 | 10,336 | $65,854 |
| Humboldt | 11 | 10,305 | $66,506 |
| Louisa | 7 | 10,296 | $70,117 |
| Hancock | 8 | 9,873 | $65,856 |
| Mitchell | 8 | 9,509 | $71,026 |
| Emmet | 5 | 9,423 | $65,373 |
| Clarke | 3 | 9,323 | $61,589 |
| Palo Alto | 8 | 9,305 | $66,131 |
| Sac | 8 | 9,219 | $70,441 |
| Franklin | 9 | 9,146 | $61,070 |
| Davis | 4 | 8,899 | $76,944 |
| Monona | 9 | 8,807 | $65,322 |
| Greene | 8 | 8,676 | $64,065 |
| Lucas | 5 | 8,671 | $65,089 |
| Decatur | 8 | 7,930 | $51,918 |
| Van Buren | 10 | 7,640 | $62,453 |
| Monroe | 3 | 7,371 | $69,974 |
| Worth | 7 | 7,102 | $67,455 |
| Fremont | 9 | 6,772 | $78,742 |
| Ida | 5 | 6,722 | $63,510 |
| Pocahontas | 8 | 6,508 | $61,172 |
| Taylor | 7 | 6,470 | $65,049 |
| Wayne | 8 | 6,278 | $62,515 |
| Adair | 5 | 6,187 | $64,716 |
| Osceola | 5 | 6,113 | $64,653 |
| Audubon | 6 | 5,170 | $58,888 |
| Ringgold | 7 | 4,293 | $72,466 |
| Adams | 4 | 3,422 | $59,818 |
Total population across listed counties: 3,189,317.