CBSA - Core Based Statistical Area Replace MSA Codes

The US Census Bureau's CBSA Information

In 2003, the Office of Management and Budget implemented Core Based Statistical Areas (CBSA) to replace MSA codes, which had been in use since about 1990. A CBSA is an area of at least 10,000 people.

MSA codes referred to Metropolitan Statistical Areas. The difference between the MSA and CBSA codes is that the newer codes also include micropolitan areas. For the most part, a micropolitan area is an urban area with a population between 10,000 and 50,000 people. If there are more than 50,000 people in an area, but the largest central city is still small it will referred to as a micropolitan area.

The CBSA codes also changed the definition of a metropolitan area. A metropolitan area required a population of at least 50,000 people, but now very large areas with 2.5 million people or more can be divided into "metropolitan divisions." The standards for the CBSA codes are much less inclusive than the MSA codes were.

When you combined CBSA codes into larger areas, it is called a Combined Statistical Area, or CSA. Standards have been set to determine whether or not a Core Based Statistical Area can be combined into a CSA. Metro and micro areas can be combined to form a CSA.

When the new CBSA codes were implemented, 49 new metropolitan areas and 550 micropolitan areas were created. There are 935 CBSA's in the United States and Puerto Rico. Since the MSA codes only recognized 284 metropolitan areas, the new codes are much more helpful for working with statistical data.