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
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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 21227 Halethorpe 410, 443, 667
Baltimore County MD 21228 Catonsville 410, 443, 667
Baltimore County MD 21234 Parkville 410, 443, 667
Baltimore County MD 21236 Nottingham 410, 443, 667
Baltimore County MD 21237 Rosedale 410, 443, 667
Baltimore County MD 21244 Windsor Mill 410, 443, 667
Baltimore County MD 21250 Baltimore 410, 443, 667
Baltimore County MD 21252 Towson 410, 443, 667
Baltimore County MD 21285 Towson 410, 443, 667
Baltimore County MD 21286 Towson 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.