References made to the City Metropolitan Statistical Area (MSA) refer to the 1999 vintage MSA. This 1999 vintage MSA geography corresponds to the metro area for which Census 2000 data were tabulated and for which many Federal agencies still produce data.
Details regarding 1999 Vintage MSAs. The territory, population, and housing units in MAs are referred to as "metropolitan." The metropolitan category is subdivided into "inside central city" and "outside central city." The territory, population, and housing units located outside territory designated "metropolitan" are referred to as "nonmetropolitan." The metropolitan and nonmetropolitan classification cuts across the other hierarchies; for example, generally there are both urban and rural territory within both metropolitan and nonmetropolitan areas.
To meet the needs of various users, the standards provide for a flexible structure of metropolitan definitions that classify each MA either as a metropolitan statistical area (MSA) or as a consolidated metropolitan statistical area (CMSA) divided into primary metropolitan statistical areas (PMSAs).
CMSA. If an area that qualifies as a metropolitan area (MA) has more than one million people, two or more primary metropolitan statistical areas (PMSAs) may be defined within it. Each PMSA consists of a large urbanized county or cluster of counties (cities and towns in New England) that demonstrate very strong internal economic and social links, in addition to close ties to other portions of the larger area. When PMSAs are established, the larger MA of which they are component parts is designated a consolidated metropolitan statistical area (CMSA). CMSAs and PMSAs are established only where local governments favor such designations for a large MA.
Central City. In each metropolitan statistical area and consolidated metropolitan statistical area, the largest place and, in some cases, additional places are designated as "central cities" under the official standards. A few primary metropolitan statistical areas do not have central cities. The largest central city and, in some cases, up to two additional central cities, are included in the title of the metropolitan area (MA); there also are central cities that are not included in an MA title. An MA central city does not include any part of that place that extends outside the MA boundary.
Metropolitan Area Title and Code. The title of a metropolitan statistical area (MSA) contains the name of its largest central city and up to two additional place names, provided that the additional places meet specified levels of population, employment, and commuting. Generally, a place with a population of 250,000 or more is in the title, regardless of other criteria.
The title of a primary metropolitan statistical area (PMSA) may contain up to three place names, as determined above, or up to three county names, sequenced in order of population size, from largest to smallest. A consolidated metropolitan statistical area (CMSA) title also may include up to three names, the first of which generally is the most populous central city in the area. The second name may be the first city or county name in the most populous remaining PMSA; the third name may be the first city or county name in the next most populous PMSA. A regional designation may be substituted for the second and/or third names in a CMSA title if local opinion supports such a designation and the federal Office of Management and Budget (OMB) deems it to be unambiguous and suitable.
The titles for all metropolitan areas (MAs) also contain the U.S. Postal Service's abbreviation for the name of each state in which the MA is located. Each MA is assigned a four-digit Federal Information Processing Standards (FIPS) code, in alphabetical order nationwide. If the fourth digit of the code is "2," it identifies a CMSA. Additionally, there is a separate set of two-digit FIPS codes for CMSAs, also assigned alphabetically.
