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 21223 Baltimore Baltimore city 410, 443, 667
MD 21224 Baltimore Baltimore city 410, 443, 667
MD 21225 Brooklyn Baltimore city 410, 443, 667
MD 21226 Curtis Bay Anne Arundel County 410, 443, 667
MD 21227 Halethorpe Baltimore County 410, 443, 667
MD 21228 Catonsville Baltimore County 410, 443, 667
MD 21229 Baltimore Baltimore city 410, 443, 667
MD 21230 Baltimore Baltimore city 410, 443, 667
MD 21231 Baltimore Baltimore city 410, 443, 667
MD 21233 Baltimore Baltimore City 410, 443, 667
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Geographic Map of Maryland

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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.