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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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Washtenaw County ZIP Codes

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

County State ZIP Code City Area Codes
Washtenaw County MI 48103 Ann Arbor 734
Washtenaw County MI 48104 Ann Arbor 734
Washtenaw County MI 48105 Ann Arbor 248, 734, 947
Washtenaw County MI 48106 Ann Arbor 734
Washtenaw County MI 48107 Ann Arbor 734
Washtenaw County MI 48108 Ann Arbor 734
Washtenaw County MI 48109 Ann Arbor 734
Washtenaw County MI 48113 Ann Arbor 734
Washtenaw County MI 48115 Bridgewater 734
Washtenaw County MI 48118 Chelsea 517, 734
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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.