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:

Allegany County Anne Arundel CountyBaltimore County
Calvert County Caroline CountyCarroll County
Cecil County Charles CountyDorchester County
Frederick County Garrett CountyHarford County
Howard County Kent CountyMontgomery County
Prince George's CountyQueen Anne's CountySt. Mary's County
Somerset County Talbot CountyWashington County
Wicomico County Worcester CountyBaltimore City

To view maps of the United States Postal Services (USPS) ZIP Codes click on the following link: /MSDC/Zipcode_map/2000/zip00idx.shtml