 List of metropolitan statistical areas

The United States Office of Management and Budget (OMB) has defined 392 metropolitan statistical areas (MSAs) for the United States, including eight for Puerto Rico.The OMB defines a Metropolitan Statistical Area as one or more adjacent counties, or county equivalents, that have at least one urban core area of at least 50,000 population, plus adjacent territory that has a high degree of social and economic integration with the core as measured by the commuting tie.