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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Baltimore County ZIP Codes

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

County State ZIP Code City Area Codes
Baltimore County MD 21057 Glen Arm 410, 443, 667
Baltimore County MD 21065 Hunt Valley 410
Baltimore County MD 21071 Glyndon 410, 443, 667
Baltimore County MD 21082 Hydes 410, 443, 667
Baltimore County MD 21087 Kingsville 410, 443, 667
Baltimore County MD 21092 Long Green 410
Baltimore County MD 21093 Lutherville Timonium 410, 443, 667
Baltimore County MD 21094 Lutherville Timonium 410
Baltimore County MD 21105 Maryland Line 410, 443, 667
Baltimore County MD 21111 Monkton 410, 443, 667
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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.