Glossary of Healthcare Access Terms
Definitions of the terms that come up when you map healthcare access: shortage designations, census geographies, provider data and access measures.
- ACS 5-Year vs 1-Year Estimates: Which to Use
ACS 5-year estimates pool 60 months of data for every area, including tracts and ZCTAs. How they differ from 1-year data, MOEs and release dates.
- CHNA: Community Health Needs Assessment Rules
A CHNA is the assessment 501(c)(3) hospitals must do at least every three years under IRC 501(r)(3). Who must, what it contains, and how a CHA differs.
- Drive-Time Access: Isochrones, Distance and 2SFCA
Drive-time access measures travel time to care: nearest-provider distance, isochrones and 2SFCA, plus HRSA and CMS time and distance thresholds.
- HPSA: Health Professional Shortage Area Defined
A HPSA is a HRSA designation for an area, population or facility short of primary care, dental or mental health providers. Types, scoring and lookup.
- MUA/MUP: Medically Underserved Areas and Populations
MUAs and MUPs are HRSA designations for areas or groups lacking primary care, scored with the Index of Medical Underservice. How they differ from HPSAs.
- NPI and Provider Taxonomy Codes: NPPES Explained
What NPIs, entity types and NUCC taxonomy codes in NPPES mean, how to filter them, and why raw NPI counts overstate active clinicians.
- Provider-to-Population Ratio: Calculation and Benchmarks
How to calculate a provider-to-population ratio, the HRSA shortage thresholds in 42 CFR Part 5, and the counting errors that distort access-gap maps.
- ZCTA vs ZIP Code: Why They Differ and How to Map
ZIP Codes are USPS delivery routes; ZCTAs are Census areas built from blocks. Why they differ, which crosswalks to use, and common ZIP mapping errors.