abstract:United States Micropolitan Statistical Areas (µSA, where the initial Greek letter mu represents "micro-"), as defined by the Office of Management and Budget (OMB), are urban areas in the United States based around an urban cluster (urban area) with a population of 10,000 to 49,999.OMB Bulletin No.
Each area retains its designation as a metropolitan or micropolitanstatisticalarea (or NECTA) within the larger combined statisticalarea (or combined NECTA) when the areas are combined.