Core-Based Statistical Area (CBSA)

Overview

Core-Based Statistical Area (CBSA) is a U.S. geographic area defined by the Office of Management and Budget that consists of one or more counties anchored by an urban center of at least 10,000 people plus adjacent counties that are socioeconomically tied to the urban center. CBSAs are classified into Metropolitan Statistical Areas (MSAs) and Micropolitan Statistical Areas based on population size.

Key Concepts

Urban core is the densely settled area that anchors a CBSA. Central county is the county containing all or the largest portion of the urban core. Outlying county is a county with strong commuting ties to the central county. Principal city is the largest city in the CBSA and other qualifying cities. Commuting threshold is the 25% minimum employment interchange for outlying counties.

Classification

TypeUrban Core PopulationExample
Metropolitan (MSA)50,000+Atlanta-Sandy Springs-Alpharetta
Micropolitan (μSA)10,000-49,999Rome, GA

CBSA Codes

  • 5-digit numeric codes assigned by OMB
  • Updated periodically (typically after each decennial census)
  • Example: 35620 = New York-Newark-Jersey City, NY-NJ-PA

Appendix

Created: 2025-12-13 | Modified: 2025-12-13

See Also