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.

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Cook County ZIP Codes

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

County State ZIP Code City Area Codes
Cook County IL 60803 Alsip 464, 708, 773, 872
Cook County IL 60804 Cicero 464, 708, 773, 872
Cook County IL 60805 Evergreen Park 464, 708, 773, 872
Cook County IL 60827 Riverdale 464, 708, 773, 872
Cook County MN 55604 Grand Marais 218, 807
Cook County MN 55605 Grand Portage 218, 807
Cook County MN 55606 Hovland 218, 807
Cook County MN 55612 Lutsen 218
Cook County MN 55613 Schroeder 218
Cook County MN 55615 Tofte 218
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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.