Metropolitan and Micropolitan

A metropolitan or micropolitan statistical area's geographic composition, or list of geographic components at a particular point in time, is referred to as its "delineation." Metropolitan and micropolitan statistical areas are delineated by the U.S. Office of Management and Budget (OMB) and are the result of the application of published standards to Census Bureau data. The standards for delineating the areas are reviewed and revised once every ten years, prior to each decennial census. Generally, the areas are delineated using the most recent set of standards following each decennial census. Between censuses, the delineations are updated annually to reflect the most recent Census Bureau population estimates. Areas based on the 2010 standards and Census Bureau data were delineated in February of 2013.

The files below show delineations of metropolitan and micropolitan statistical areas and related statistical areas delineated by OMB since February 2013. Related statistical areas include New England City and Town Areas (NECTAs), which are conceptually similar to metropolitan and micropolitan statistical areas, but are delineated using cities and towns instead of counties; Combined Statistical Areas, which are aggregates of adjacent metropolitan or micropolitan statistical areas that are linked by commuting ties; and Combined New England City and Town Areas, which are aggregates of adjacent NECTAs that are linked by commuting ties.

Office of Management and Budget (OMB) Bulletins

Delineation Files

For delineations of metropolitan areas prior to 2013, see the historical delineations page.