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
All states and U.S. territories
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State directory

Maryland ZIP Codes

Complete postal directory, details, and geographic map for the State of Maryland.

State ZIP Code City County Area Codes
MD 21783 Smithsburg Washington County 223, 227, 240, 301, 717
MD 21784 Sykesville Carroll County 410, 443, 667
MD 21787 Taneytown Carroll County 227, 240, 301, 410, 443, 667
MD 21788 Thurmont Frederick County 227, 240, 301
MD 21790 Tuscarora Frederick County 227, 240, 301, 571, 703
MD 21791 Union Bridge Carroll County 227, 240, 301, 410, 443, 667
MD 21792 Unionville Frederick County 240
MD 21793 Walkersville Frederick County 227, 240, 301
MD 21794 West Friendship Howard County 410, 443, 667
MD 21795 Williamsport Washington County 227, 240, 301, 304, 681
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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.