Metropolitan Statistical Area (MSA): OMB Definition & Use

Definition

A Metropolitan Statistical Area (MSA) is a geographic entity delineated by the U.S. Office of Management and Budget (OMB) for federal statistical purposes. It comprises a core urban area of ≥50,000 population plus adjacent counties with high social/economic integration (measured by commuting ties).

Key Criteria

• Core: Urbanized area ≥50,000 (Census Bureau).
• Outlying counties: ≥25% of employed residents work in the core, or ≥25% of jobs in the county are held by core residents.
• May cross state lines (e.g., NY-NJ-CT-PA MSA).

Related Terms

• Micropolitan Statistical Area: Core 10,000–49,999.
• Combined Statistical Area (CSA): Adjacent MSAs/μSAs with employment interchange ≥15%.
• Metropolitan Division: Subdivision of an MSA ≥2.5 million population.

Applications

Used by Census Bureau, BLS, HUD, CDC, and researchers for demographic, economic, housing, and health data tabulation. Not a political/administrative boundary.