United States metropolitan area

In the United States, the Office of Management and Budget (OMB) has produced a formal definition of metropolitan areas, which are organized around county boundaries. These are referred to as "Metropolitan Statistical Areas" (MSAs).

As of February 2005, there is now an additional classification, that of a “Metropolitan Division.” The term Metropolitan Division is used to refer to a county or group of counties within a Metropolitan Statistical Area that has a population core of at least 2.5 million. While a Metropolitan Division is a subdivision of a larger Metropolitan Statistical Area, it often functions as a distinct social, economic, and cultural area within the larger region.

The following is a list of the 25 most populated metropolitan statistical areas and Metropolitan Divisions in the United States, according to the 2000 Census:

* Not necessarily equivalent to the Census definition of the metropolitan area.
** This metropolitan area of Detroit does not include certain outlying areas considered to be in Southeast Michigan, such as Genesee and Livingston Counties, nor does it include Canadian cities. A larger metropolitan area containing the Windsor, Ontario area is used internationally.
*** The Bay Area is a much larger area than the OMB's rather limited MSA, corresponding more closely to the San Jose - San Francisco - Oakland Combined Statistical Area
**** The main cities of the Twin Cities are generally considered to be Minneapolis and St. Paul; Bloomington is generally considered to be a suburb of the two even though it is in a three-way tie for the third largest city in Minnesota.

For a complete list, see List of United States metropolitan statistical areas by population.

See also