Technology Transfer Network / NAAQS
Ozone Implementation
Statistics Based on MSA Notice
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Statistics Based on MSA Notice of Core-Based Statistical Areas Number Pct. of 1990 Number of Areas U.S. Population of Counties Megapolitan Areas 35 45.0 267 Macropolitan Areas 311 33.3 616 Micropolitan Areas 485 10.8 562 CBSA totals 831 89.1 1,445 Outside CBSAs 10.9 1,696 Population in cores: Megapolitan areas: 95,876,292 Macropolitan areas: 56,579,276 Micropolitan areas: 9,110,530 CBSA populations: Megapolitan areas: 111.9 million Macropolitan areas: 82.8 million Micropolitan areas: 26.9 million Outside CBSAs: 27.1 million