Methodology & Data Sources

Data sources

US5 uses public data from the U.S. Census Bureau, IRS, NOAA, USDA, EPA, FEMA, NCES, National Park Service, and Department of Veterans Affairs.

Geographic unit

ZIP-level statistics primarily use Census ZIP Code Tabulation Areas (ZCTAs). ZCTAs approximate USPS delivery areas and do not always match postal boundaries exactly.

Aggregation

State, county, city, area-code, congressional-district, and DMA pages aggregate published ZIP records. Averages are population-weighted or simple averages depending on the source metric.

Updates and limitations

Source datasets follow their agencies’ release schedules. Values are informational and should be verified against official sources before financial, legal, medical, or real-estate decisions.