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 51654 Thurman Fremont County 402, 531, 712
IA 51656 Yorktown Page County 712
IA 52001 Dubuque Dubuque County 563, 608
IA 52002 Dubuque Dubuque County 563
IA 52003 Dubuque Dubuque County 563, 779, 815
IA 52004 Dubuque Dubuque County 563
IA 52030 Andrew Jackson County 563
IA 52031 Bellevue Jackson County 563, 779, 815
IA 52032 Bernard Dubuque County 563
IA 52033 Cascade Dubuque County 319, 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.