A metropolitan complex of one million or more population, containing two or more component parts designated as primary metropolitan statistical areas, or PMSAs.

As used in the Clean Air Act (CAA) and the Energy Policy Act (EPACT), geographical areas defined by the Bureau of Census that includes cities or combinations of multiple cities with large population concentrations. The Metropolitan Statistical Area (MSA) refers to geographical areas that generally include one city with a smaller population concentration. For certain programs (e.g., oxygenated gasoline), the CAA adds definitions employed by the Office of Management and Budget. For all EPACT mandates for AFVs and for the CAA Clean-Fuel Vehicle Program, use of the terms CMSA and MSA are delimited to areas with a 1980 population of 250,000 or more, as determined by the Bureau of the Census.

A Metropolitan Statistical Area with a population greater than 1 million. (See also, Metropolitan Statistical Area).

Adjoining Metropolitan Statistical Areas (MSAs) having a combined population of one million or more. When combined into a CMSA, each component metropolitan area is referred to as a Primary Metropolitan Statistical Area (PMSA).

(CMSA) A geographic entity defined by the federal Office of Management and Budget for use by federal statistical agencies. An area becomes a CMSA if it meets the requirements to qualify as a metropolitan statistical area, has a population of 1,000,000 or more, if component parts are recognized as primary metropolitan statistical areas, and local opinion favors the designation. (Census)