Iowa ZIP Codes

ZIP codes: 1,055
Cities & towns: 934
Counties: 99
Area codes: 5

How Iowa ZIP codes are numbered

500xx–528xx

The first three digits identify the sectional center facility that processes mail for a region, so an Iowa ZIP code can be placed geographically from its prefix alone. Each row names the city holding the most codes in that prefix.

Iowa three-digit ZIP prefixes, the codes in each, and the city that holds the most of them.
Prefix	ZIP codes	Main area
500xx	68	Ames
501xx	69	Galt
502xx	65	West Des Moines
503xx	55	Des Moines
504xx	57	Mason City
505xx	75	Clarion
506xx	70	Cedar Falls
507xx	5	Waterloo
508xx	28	Afton
509xx	8	Des Moines
510xx	55	Akron
511xx	9	Sioux City
512xx	20	Alvord
513xx	23	Arnolds Park
514xx	32	Arcadia
515xx	57	Council Bluffs
516xx	21	Shenandoah
520xx	46	Dubuque
521xx	33	Calmar
522xx	50	Iowa City
523xx	53	Marengo
524xx	14	Cedar Rapids
525xx	50	Fairfield
526xx	36	Argyle
527xx	47	Clinton
528xx	9	Davenport

Where Iowa's communities sit

Each point is an Iowa community with a published ZIP code list, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Iowa cities by ZIP code count

largest 25

Area codes serving Iowa

Scope every ZIP code recorded in Iowa. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. The map outline is a convex envelope of published places, not a state boundary.