CBSA Codes were introduced in June 2003 by the Executive Branch of the United States under the Office of Management and Budget as a way to determine which areas in the USA had a high-degree of "cohesiveness" or interaction with each other. For example, all the cities and towns around Chicago, IL interact primarily with Chicago - knowing this information helps companies better identify their customers as well as divide sales territories.
For larger metro areas, this database also includes the Metropolitan Division (if any) in which the ZIP code lies. Not all ZIP Codes have a CBSA code assigned to them such as rural and "middle of nowhere" ZIP Codes.
CBSAs and Metropolitan Divisions are five-digit numeric codes assigned to the 960 metropolitan, micropolitan, and division statistical areas defined by the Office of Management and Budget (OMB), a part of the administrative branch of the Federal Government.
USA - CBSA Database. The database includes ZIP Code, County FIPS, CSA Code, CSA Name, CBSA Code, CBSA Name, CBSA Type, Div Code, Div Name. The ZIP Code list is available in the following formats: Microsoft Excel 97 (or later), Microsoft Access 97 & 2000 (or later), comma-separated values, fixed-width format, and tab-delimited format. All formats are included with your purchase, and they can be imported into most databases and spreadsheets.