Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/IA/MOST-TAX-RETURNS

ZIP Codes With the Most Tax Returns Filed in Iowa

What this measures. Number of individual income tax returns filed. A rough proxy for how many households a ZIP code contains, available where census figures are not. Source: IRS Statistics of Income, ZIP code data, data release 2026-10-12.

# ZIP City County Returns filed
1 50023 Ankeny Polk 22,270
2 52302 Marion Linn 20,660
3 52404 Cedar Rapids Linn 20,230
4 52722 Bettendorf Scott 19,930
5 52402 Cedar Rapids Linn 19,660
6 52001 Dubuque Dubuque 19,480
7 50266 West Des Moines Dallas 19,450
8 50613 Cedar Falls Black Hawk 18,520
9 50317 Des Moines Polk 17,250
10 51503 Council Bluffs Pottawattamie 16,990
11 50315 Des Moines Polk 16,790
12 50265 West Des Moines Polk 16,580
13 50322 Urbandale Polk 15,730
14 51501 Council Bluffs Pottawattamie 15,310
15 50310 Des Moines Polk 15,160
16 50021 Ankeny Polk 14,940
17 50263 Waukee Dallas 14,310
18 50701 Waterloo Black Hawk 14,270
19 52240 Iowa City Johnson 14,110
20 52761 Muscatine Muscatine 14,010
21 50010 Ames Story 13,960
22 50158 Marshalltown Marshall 13,900
23 51106 Sioux City Woodbury 13,680
24 52601 Burlington Des Moines 13,280
25 50401 Mason City Cerro Gordo 13,150
26 52806 Davenport Scott 13,060
27 52501 Ottumwa Wapello 12,980
28 52405 Cedar Rapids Linn 12,360
29 52804 Davenport Scott 12,230
30 50501 Fort Dodge Webster 11,960
31 50131 Johnston Polk 11,910
32 52732 Clinton Clinton 11,430
33 50014 Ames Story 11,320
34 50009 Altoona Polk 11,020
35 52241 Coralville Johnson 10,910
36 52403 Cedar Rapids Linn 10,830
37 52317 North Liberty Johnson 10,730
38 51104 Sioux City Woodbury 10,360
39 50320 Des Moines Polk 10,140
40 52246 Iowa City Johnson 9,910
41 52245 Iowa City Johnson 9,860
42 52803 Davenport Scott 9,850
43 50702 Waterloo Black Hawk 9,600
44 50125 Indianola Warren 9,460
45 50325 Clive Polk 8,980
46 50208 Newton Jasper 8,850
47 52002 Dubuque Dubuque 8,640
48 50323 Urbandale Dallas 8,540
49 50111 Grimes Polk 8,400
50 50211 Norwalk Warren 7,890

Showing the top 50 of 823 ZIP codes in Iowa that have this figure . 50023 ranks 1st at 22,270, against 7,890 in 50th place.

Other rankings for Iowa

Cite this page

zipcodes.pro. “ZIP Codes With the Most Tax Returns Filed in Iowa.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/ia/most-tax-returns

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