Metropolitan, micropolitan, and combined statistical areas are defined by the Office of Management and Budget (OMB). Metropolitan and micropolitan statistical areas (collectively known as core based statistical areas) consist of one or more counties. Combined statistical areas consist of multiple metropolitan or micropolitan statistical areas. To learn more about metropolitan, micropolitan, and combined statistical areas, please visit the Census Bureau's Metropolitan and Micropolitan Statistical Areas.
The boundaries and titles depicted on these maps reflect the definitions described by OMB on June 6, 2003. These definitions are based on Census 2000 data.
The boundaries and titles depicted on these revised maps reflect the definitions described by OMB on June 6, 2003 with the exception of three titles in New York that were subsequently revised.
OMB further revised the metropolitan, micropolitan, and combined statistical area definitions based on new population estimates in December 2003. A map of the new definitions is now available. The December definition is based on the Census Bureau's July 1, 2001 and July 1, 2002 population estimates for cities and towns, and also on local opinion in specified circumstances.