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U.S. ZIP Codes Database 2026

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St. Mary's County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in St. Mary's County.

County State ZIP Code City Area Codes
St. Mary's County MD 20606 Abell 227, 240, 301
St. Mary's County MD 20609 Avenue 227, 240, 301
St. Mary's County MD 20618 Bushwood 227, 240, 301
St. Mary's County MD 20619 California 227, 240, 301, 410, 443, 667
St. Mary's County MD 20620 Callaway 227, 240, 301
St. Mary's County MD 20621 Chaptico 227, 240, 301
St. Mary's County MD 20624 Clements 227, 240, 301
St. Mary's County MD 20626 Coltons Point 227, 240, 301
St. Mary's County MD 20627 Compton 240
St. Mary's County MD 20628 Dameron 227, 240, 301
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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.