larger statistical entity known as a combined statistical area (CSA) when the employment interchange measure (EIM) reaches 15% or more. CBSAs are subdivided into MSAs (formed around urban areas of at least 50,000 in population) and micropolitan statistical areas (μSAs), which are CBSAs built around an urban cluster of at least 10,000 in population but less than 50,000 in population. Some metropolitan areas may include multiple cities below 50,000 people, but combined have over 50,000 people. Previous terms that are no longer used include standard metropolitan statistical area (SMSA) and primary metropolitan statistical area (PMSA). 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. United States The 384 MSAs of the United States (the 50 states and the District of Columbia) are ranked, including: The MSA rank by population as of July 1, 2021, 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, 2021, 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, 2021 The combined statistical area (CSA) if it is designated and the MSA is a component Puerto Rico This sortable table lists the eight metropolitan statistical areas (MSAs) of Puerto Rico including: The MSA rank by population as of July 1, 2021, 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, 2021, 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, 2021 The combined statistical area (CSA) if the MSA is a component See also Demographics of the United States United States Census Bureau List of U.S. states and territories by population List of metropolitan areas of the United States List of United States cities by population List of United States counties and