The Archdiocese is broken down into two Vicariates, smaller geographic areas within the Archdiocese. In addition, each Vicariate is broken down into regions, all of which are overseen by one of the auxiliary bishops.

St. John Neumann Vicariate - view parishes
Auxiliary Bishop: Most Reverend Denis J. Madden
Geographical Area: Baltimore County, Baltimore City, Harford County
Regions within the Vicariate: East Baltimore County Region, North Baltimore County Region, West Baltimore County Region, Harbor East Region, Harbor West Region, Metro East Region, Metro West Region, Harford Region

St. Elizabeth Ann Seton Vicariate - view parishes
Auxiliary Bishop: Most Reverend Mitchell T. Rozanski
Geographical Area: Allegany County, Anne Arundel County, Carroll County, Frederick County, Garrett County, Howard County, Washington County
Regions within the Vicariate: Anne Arundel Region, Central Region, South Central Region, Western Region