USAviz

Methodology

USA Viz combines public datasets into consistent place pages. Each page focuses on a single geography (ZIP, county, metro, state, or area code) and highlights a bounded set of indicators with clear source and vintage notes.

Last updated: January 30, 2026

Place Types and Boundaries

  • ZIP codes: ZIP pages use Census ZCTAs for mapping and overlap estimates. ZCTAs are approximations and do not perfectly match USPS delivery routes.
  • Counties and states: Boundaries follow U.S. Census Bureau geography (TIGER/Line) where applicable.
  • Metro areas: Metros follow OMB Core Based Statistical Areas (CBSAs). County membership is defined by OMB delineations.
  • Area codes: Area codes are telecom numbering regions. Coverage can cross city/county lines and may change over time (splits/overlays).

Native vs. Context Metrics

We try to show indicators at the place's native geography (for example, ZIP-level ACS estimates on ZIP pages). When a dataset does not publish at a given geography, we either omit that indicator for the page type or show it as broader-area context (such as a county or metro rollup) and label it accordingly.

Health note: CDC PLACES publishes modeled estimates. Some PLACES measures can be unavailable for specific places in a given release; those values are shown as Not available. Metro and state health summaries are derived from county-level PLACES estimates when available.

Ranking Context

When shown, "top quartile" / "bottom quartile" labels refer to percentile buckets within a comparison set (for example, ZIPs within the same county). These are descriptive comparisons, not quality ratings.

Benchmarks (US and peer)

  • US: National benchmark derived from the same underlying dataset used on the page. Benchmarks can differ slightly by geography type (ZIP vs county vs metro vs state) because sources publish different series at different levels.
  • Peer median: The median value within a relevant peer set (for example, other ZIPs in the same county). The peer set varies by page type and is shown where available.
  • Metric definitions: For example, poverty rate reflects ACS poverty status (people below the federal poverty line). Other websites may show different national values if they use a different definition or universe.

Data Freshness

Each place page includes a compact "Data freshness" block listing key vintages (ACS year, CDC PLACES year, storms last event date, etc.).

For dataset links and notes, visit Sources.

Contact

Questions about methodology: data@usaviz.com.