Metropolitan statistical area

s (CBSAs) of the United States and Puerto Rico as of 2023; the 393 MSAs are shown in green. CBSAs are delineated on the basis of a central contiguous area of relatively high population density, known as an urban area. The counties containing the core urban area are known as the "central counties" of the CBSA; these are defined as having at least 50% of their population living in urban areas of at least 10,000 in population. Additional surrounding counties, known as "outlying counties", can be included in the CBSA if these counties have strong social and economic ties to the central county or counties as measured by commuting and employment. Outlying counties are included in the CBSA if 25% of the workers living in the county work in the central county or counties, or if 25% of the employment in the county is held by workers who live in the central county or counties. Adjacent CBSAs are merged into a single CBSA when the central county or counties of one CBSA qualify as an outlying county or counties to the other CBSAs. Metropolitan statistical areas containing over 2.5 million people can also be further divided into metropolitan divisions. On January 19, 2021, OMB submitted a regulation for public comment that would increase the minimum population needed for an urban area population to be a metropolitan statistical area to be increased from 50,000 to 100,000. It ultimately decided to keep the minimum at 50,000 for the 2020 cycle. On July 21, 2023, the Office of Management and Budget released revised delineations of the various CBSAs in the United States. ==History==

The Census Bureau created the metropolitan district for the 1910 census as a standardized classification for large urban centers and their surrounding areas. The original threshold for a metropolitan district was 200,000, but was lowered to 100,000 in 1930, and lowered again to 50,000 in 1940. The metropolitan districts were replaced by standard metropolitan areas (SMAs) in the 1950 census, which were defined by the Bureau of the Budget (now the Office of Management and Budget) and later renamed to standard metropolitan statistical areas (SMAs) in 1959. The modern metropolitan statistical area was created in 1983 amid a large increase in the number of eligible markets, which grew from 172 in 1950 to 288 in 1980; the core based statistical area (CBSA) was introduced in 2000 and defined in 2003 with a minimum population of 10,000 required for micropolitan areas and 50,000 for urban areas. == United States ==

The 387 MSAs in the United States, including those in all 50 states and the national capital of Washington, D.C. are ranked, including: • The MSA rank by population as of July 1, 2025, as estimated by the United States Census Bureau • The MSA name as designated by the United States Office of Management and Budget ==Puerto Rico==

This sortable table lists the six metropolitan statistical areas (MSAs) of Puerto Rico including: • The MSA rank by population as of July 1, 2025, as estimated by the United States Census Bureau • The MSA name as designated by the United States Office of Management and Budget • The MSA population as of July 1, 2025, as estimated by the United States Census Bureau • The MSA population as of April 1, 2020, as enumerated by the 2020 United States census • The percent MSA population change from April 1, 2020, to July 1, 2025 • The combined statistical area (CSA) if the MSA is a component ==See also==