In the United States, a metropolitan statistical area (MSA) is a geographical region with a relatively high population density at its core and close economic ties throughout the region. Such regions are not legally incorporated as a city or town would be and are not legal administrative divisions like counties or separate entities such as states. As a result, sometimes the precise definition of a given metropolitan area will vary between sources. The statistical criteria for a standard metropolitan area were defined in 1949 and redefined as a metropolitan statistical area in 1983.
United States micropolitan statistical areas, as defined by the Office of Management and Budget (OMB), are labor market and statistical areas in the United States centered on an urban cluster with a population of at least 10,000 but fewer than 50,000 people. The micropolitan area designation was created in 2003. Like the better-known metropolitan statistical areas, a micropolitan area is a geographic entity used for statistical purposes based on counties and county equivalents. On July 21, 2023, the Office of Management and Budget released revised delineations of the various CBSAs in the United States, which recognized 542 micropolitan areas in the United States, four of which are in Puerto Rico.
Combined statistical area (CSA) is a United States Office of Management and Budget (OMB) term for a combination of adjacent metropolitan (MSA) and micropolitan statistical areas (μSA) across the 50 U.S. states and the territory of Puerto Rico that can demonstrate economic or social linkage. CSAs were first designated in 2003. OMB defines a CSA by various combinations of adjacent metropolitan and micropolitan areas with economic ties measured by commuting patterns. CSAs retain their own designations as metropolitan or micropolitan statistical areas in their respective larger combined statistical areas.
The U.S. State of Illinois currently has 47 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated 14 combined statistical areas, 12 metropolitan statistical areas, and 21 micropolitan statistical areas in Illinois. As of 2023, the largest of these is the Chicago-Naperville, IL-IN-WI CSA, comprising the area around Illinois' largest city, Chicago.
The U.S. State of Ohio currently has 55 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated 11 combined statistical areas, 15 metropolitan statistical areas, and 29 micropolitan statistical areas in Ohio. As of 2023, the largest of these is the Cleveland-Akron-Canton, OH CSA, comprising Cleveland and other cities in the northeast region of the state.
The United States Commonwealth of Pennsylvania currently has 48 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated 12 combined statistical areas, 16 metropolitan statistical areas, and 20 micropolitan statistical areas in Pennsylvania. As of 2023, the largest of these is the Philadelphia-Reading-Camden, PA-NJ-DE-MD CSA, comprising the area around the state's largest city of Philadelphia in the southeast region of the state.
The U.S. state of New York currently has 34 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated seven combined statistical areas, 13 metropolitan statistical areas and 14 micropolitan statistical areas in New York. As of 2023, the largest of these is the New York-Newark, NY-NJ-CT-PA CSA, which includes New York City and its surrounding suburbs; with over 21 million people, it is the largest primary statistical area in the United States.
The U.S. State of Connecticut currently has nine statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated two combined statistical areas, five metropolitan statistical areas, and two micropolitan statistical areas in Connecticut. As of 2023, the largest of these in the state is the New Haven-Hartford-Waterbury, CT CSA, encompassing the entire state outside of the Bridgeport-Stamford-Danbury, CT MSA in the southwest.
The U.S. State of Wisconsin currently has 40 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated 11 combined statistical areas, 15 metropolitan statistical areas, and 14 micropolitan statistical areas in Wisconsin. As of 2023, the largest of these is the Milwaukee-Racine-Waukesha, WI CSA, comprising the area around the Wisconsin's largest city, Milwaukee.
The U.S. State of Hawaiʻi currently has four statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated two metropolitan statistical areas and two micropolitan statistical areas in Hawaiʻi. As of 2023, the most populous of these is the Urban Honolulu, HI MSA, anchored by Hawaiʻi's capital and largest city, Honolulu, on the island of Oahu.
The U.S. State of Montana currently has seven statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated five metropolitan statistical areas and two micropolitan statistical areas in Montana. As of 2023, the largest of these is the Billings, MT MSA, comprising the area surrounding Montana's largest city of Billings.
The U.S. State of Alabama currently has 35 statistical areas that have been delineated by the Office of Management and Budget (OMB).
The United States District of Columbia(Washington, D.C.) is the primary city of two statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated the Washington-Arlington-Alexandria, DC-VA-MD-WV MSA and the more extensive Washington-Baltimore-Arlington, DC-MD-VA-WV-PA CSA.
The U.S. State of Virginia currently has 19 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated four combined statistical areas, 11 metropolitan statistical areas, and four micropolitan statistical areas in Virginia. As of 2023, the largest of these is the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA CSA, comprising Washington, D.C. and its suburbs.
The U.S. State of West Virginia currently has 20 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated five combined statistical areas, 10 metropolitan statistical areas, and five micropolitan statistical areas in West Virginia. As of 2023, the largest of these is the Charleston-Huntington-Ashland, WV-OH-KY CSA, which includes West Virginia's capital and largest city, Charleston.
The U.S. State of Nebraska currently has 16 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated three combined statistical areas, four metropolitan statistical areas, and nine micropolitan statistical areas in Nebraska. As of 2023, the largest of these is the Omaha-Fremont, NE-IA CSA, comprising the area around Nebraska's largest city, Omaha.
The U.S. State of Oregon currently has 24 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated four combined statistical areas, eight metropolitan statistical areas, and 12 micropolitan statistical areas in Oregon. As of 2023, the largest of these is the Portland-Vancouver-Salem, OR-WA CSA, anchored by Oregon's largest city, Portland and including its capital, Salem.
The U.S. State of South Carolina currently has 20 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated four combined statistical areas, ten metropolitan statistical areas, and six micropolitan statistical areas in South Carolina. As of 2023, the largest of these is the Greenville-Spartanburg-Anderson, SC CSA, comprising the area around Greenville in the state's Upcountry.
The Commonwealth of Puerto Rico currently has 13 statistical areas that have been delineated by the United States Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated three combined statistical areas, six metropolitan statistical areas, and four micropolitan statistical areas in Puerto Rico. As of 2023, the largest of these is the San Juan-Bayamón, PR CSA, comprising the area around San Juan, Puerto Rico's capital and largest city.
