ZIP Code Tabulation Areas (ZCTAs)

The U.S. Census Bureau created ZCTAs in order to provide approximate area representations of the United States Postal Services (USPS) ZIP Code service areas. The ZCTAs are NOT the same as the U.S. Postal Service Zip Codes in that ZCTAs follow census block boundaries. In contrast, U.S. Postal Service ZIP Codes serve addresses with no correlation to census block boundaries; therefore, the area covered by a ZCTA may include mailing addresses associated with ZIP Codes that are not the same as the ZCTA.

For more information on ZCTAs visit the U.S. Census Bureau's website at: https://www.census.gov/geo/reference/zctas.html​​

Allegany County Anne Arundel County Baltimore County
Calvert County Caroline County Carroll County
Cecil County Charles County Dorchester County
Frederick County Garrett County Harford County
Howard County Kent County Montgomery County
Prince George's County Queen Anne's County St. Mary's County
Somerset County Talbot County Washington County
Wicomico County Worcester County Baltimore City​


View maps of the United States Postal Services (USPS) ZIP Codes  at this page:  Zip Code Boundary Area Files