Built on government data. Updated monthly.
Every score on CartoChrome is traceable to a public, auditable data source. No paid feeds. No proprietary black boxes. If something looks wrong, tell us — and it'll be fixed in the next pipeline run.
21
Public data sources
4M+
Provider profiles
80K+
Facilities indexed
30K
ZIP codes scored
Last full pipeline run:
Methodology
The CartoChrome Healthcare Access Score uses Enhanced 2-Step Floating Catchment Area (E2SFCA) — the peer-reviewed method published by Luo and Qi in 2009 and refined across dozens of follow-up studies. Eight weighted components (primary care, emergency, hospital inpatient, specialist, mental health, preventive, dental, telehealth) produce a base access score, which is then multiplied by a penalty-only Social Determinants of Health modifier built from six Census sub-indices (insurance, economic, transport, health literacy, disability, age).
Weights are calibrated by constrained Elastic Net regression against CDC PLACES utilization data with 5-fold cross-validation — not by expert opinion. The full specification, including every equation, weight, and clinical guardrail, lives in the methodology document.
The 21 data sources
Every source below has a public download endpoint, a published update cadence, and a long history of being cited in peer-reviewed health-services research. Click through to verify at the source.
Public data sources feeding the CartoChrome score
- CMS NPPES — National Provider Identifier RegistryUpdated Mar 2026
Every NPI-registered physician and practice in the US. Refreshed monthly with weekly deltas.
- CMS Doctors and Clinicians (Physician Compare)Updated Feb 2026
Quality measures, Medicare participation, and group-practice affiliations.
- CMS Provider of Services (POS)Updated Jan 2026
Master list of Medicare-certified hospitals and facilities with bed counts and ownership.
- CMS Hospital CompareUpdated Feb 2026
Star ratings, mortality rates, readmissions, and patient-experience scores.
- CMS Care CompareUpdated Feb 2026
Nursing homes, home-health, and dialysis facilities with quality metrics.
- SAMHSA Behavioral Health Treatment LocatorUpdated Jan 2026
Mental-health and substance-use treatment facilities, updated quarterly.
- FDA MQSA Mammography FacilitiesUpdated Mar 2026
FDA-certified mammography screening locations.
- Census ACS 5-Year EstimatesUpdated Dec 2025
Demographics, insurance, income, housing, transport, and disability by ZCTA.
- Census TIGER/Line ShapefilesUpdated Dec 2025
ZIP/ZCTA polygon geometries that drive the choropleth map.
- HUD USPS ZIP–ZCTA CrosswalkUpdated Jan 2026
Maps mailing ZIPs to Census ZCTAs for reliable joins.
- USDA RUCA CodesUpdated Sep 2025
Rural-Urban Commuting Area codes that calibrate catchment-area tiers.
- HRSA HPSA DesignationsUpdated Feb 2026
Federally-designated Health Professional Shortage Areas.
- NUCC Taxonomy CodesUpdated Jan 2026
Provider-specialty classification mapping NPI to our 8 score components.
- CDC PLACESUpdated Oct 2025
Census-tract health measures used as the primary calibration target.
- CDC WONDER MortalityUpdated Nov 2025
County-level mortality data used for score validation.
- County Health RankingsUpdated May 2025
Robert Wood Johnson Foundation county-level health outcomes (validation target).
- CMS Geographic VariationUpdated Jan 2026
Per-capita Medicare spending and utilization by geography.
- FCC Broadband Data CollectionUpdated Jan 2026
Broadband availability. Feeds the telehealth modifier.
- IMLC Interstate Medical Licensure Compact
State-by-state cross-border licensure for telehealth filtering.
- HRSA Health Center Program DataUpdated Jan 2026
Federally Qualified Health Centers (FQHCs) and look-alikes.
- Census Bureau GeocoderUpdated Mar 2026
Address-to-coordinate resolution for the geocoding pipeline.
Update cadence
Nothing updates ad-hoc. Every source is on a scheduled Render Cron Job with pipeline telemetry.
Weekly
NPPES delta, HHS OIG exclusion list
Mondays, 05:00 UTC
Monthly
Full NPPES file, Hospital Compare, facility ratings
1st of month, 04:00 UTC
Quarterly
CMS POS, Care Compare, SAMHSA, HPSA designations
Q1/Q2/Q3/Q4 first week
Annually
Census ACS, RUCA, County Health Rankings, CDC PLACES
On source release
Security & privacy
We only index data that is already public. No patient records, no PHI, no tracking signals tied to individual health queries.
Only public data, aggregated at the ZIP level
Provider profiles come from the NPPES directory — the same registry any patient or journalist can download. Demographics are Census ACS at the ZCTA level; we never break them below 250 residents.
HTTPS-only, encrypted at rest
Every route is HTTPS with HSTS preload. The PostgreSQL database and its backups are encrypted at rest, and access is SSO-gated.
No tracking of medical queries
We never correlate a search for a condition with any personally identifiable information. Anonymous page-view analytics only; no ad-targeting pixels on score pages.
Auditable account deletion
If you have a CartoChrome account, you can export and delete your data from the dashboard at any time. No email ticket required.
Read the full privacy policy and terms of service.
Found a data error?
Data at our scale is never 100% correct. Physicians retire, practices move, hospital names change. If a provider, facility, or score looks wrong, tell us — we triage every report within 3 business days.
Include the ZIP code, NPI, or facility ID plus a short description. For licensing or press inquiries, use contact@cartochrome.com.
Research & citations
The scoring algorithm cites 36 peer-reviewed papers directly. Our research library contains 99 — spanning neighborhood access, rural care, surgery, cancer, mental health, and emergency medicine.
99
Papers in the research library
36
Cited in the scoring algorithm
10
Health domains covered
Full bibliography lives in Appendix D of the methodology document.
Frequently asked questions
- How often do healthcare access scores update?
- The full CartoChrome pipeline runs on the first of every month. Provider data (NPPES) refreshes weekly via delta updates, and the HHS OIG exclusion list — which surfaces fraud/abuse flags — runs every Monday. Census ACS and CDC PLACES benchmarks update annually on their source cadence.
- Where does CartoChrome get its data?
- From 21 free, public, government data sources — including CMS NPPES (the NPI provider registry), CMS Hospital Compare, SAMHSA, HRSA HPSA designations, Census ACS, CDC PLACES, and USDA RUCA codes. We use zero paid data, zero proprietary databases, and zero Data Use Agreements. Every score is reproducible by anyone with the technical skill and the public APIs.
- How accurate is the Healthcare Access Score?
- We validate against CDC PLACES (target Pearson r > 0.65), County Health Rankings (r > 0.70), and HRSA HPSA concordance (> 70% agreement). The scoring engine uses E2SFCA — the peer-reviewed method Luo & Qi published in 2009 and that has been refined across 36 of the papers we cite in our methodology.
- What do I do if I find a data error?
- Email corrections@cartochrome.com with the ZIP code, provider NPI, or facility ID and a description of what looks wrong. We triage every report within 3 business days. NPPES and CMS corrections get re-ingested automatically on the next pipeline run once fixed at the source; our own layer fixes (geocoding, specialty mapping) ship as a patch release.
- Does CartoChrome sell personal data?
- No. CartoChrome surfaces only publicly available provider and facility data — the same information you can download from data.cms.gov — and aggregated Census statistics at the ZIP level. We never expose, sell, or share individual patient data. See our privacy policy for the full picture.