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U.S. ZIP Codes Database 2026

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Poweshiek County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in Poweshiek County.

County State ZIP Code City Area Codes
Poweshiek County IA 50112 Grinnell 641
Poweshiek County IA 50157 Malcom 641
Poweshiek County IA 50171 Montezuma 641
Poweshiek County IA 50242 Searsboro 641
Poweshiek County IA 52211 Brooklyn 641
Poweshiek County IA 52221 Guernsey 319, 641
Poweshiek County IA 52222 Deep River 319, 641
Poweshiek County IA 52232 Hartwick 319, 641

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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.