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
Maps and coordinates
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 21709 Frederick Frederick County 240
MD 21710 Adamstown Frederick County 227, 240, 301
MD 21711 Big Pool Washington County 223, 227, 240, 301, 304, 681, 717
MD 21713 Boonsboro Washington County 227, 240, 301
MD 21714 Braddock Heights Frederick County 227, 240, 301
MD 21715 Brownsville Washington County 227, 240, 301
MD 21716 Brunswick Frederick County 227, 240, 301, 540, 826
MD 21717 Buckeystown Frederick County 227, 240, 301
MD 21718 Burkittsville Frederick County 227, 240, 301
MD 21719 Cascade Washington County 223, 227, 240, 301, 717
Page 51 of 63

Geographic Map of Maryland

Postal context

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.