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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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Johnson County ZIP Codes

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

County State ZIP Code City Area Codes
Johnson County IA 52322 Oxford 319
Johnson County IA 52333 Solon 319, 563
Johnson County IA 52338 Swisher 319
Johnson County IA 52340 Tiffin 319
Johnson County IA 52755 Lone Tree 319
Johnson County IL 62909 Boles 618
Johnson County IL 62912 Buncombe 618
Johnson County IL 62923 Cypress 618
Johnson County IL 62939 Goreville 618
Johnson County IL 62943 Grantsburg 618
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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.