U.S. postal lookup

U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

42,735 verified records
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Iowa ZIP Codes

Complete postal directory, details, and geographic map for the State of Iowa.

State ZIP Code City County Area Codes
IA 52133 Castalia Winneshiek County 563
IA 52134 Chester Howard County 507, 563, 641
IA 52135 Clermont Fayette County 563
IA 52136 Cresco Howard County 507, 563
IA 52140 Dorchester Allamakee County 507, 563
IA 52141 Elgin Fayette County 563
IA 52142 Fayette Fayette County 563
IA 52144 Fort Atkinson Winneshiek County 563
IA 52146 Harpers Ferry Allamakee County 563, 608
IA 52147 Hawkeye Fayette County 563
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.