AINPI · CMS National Provider Directory audit
21.7M FHIR R4 records from the 2026-05-08 bulk public-use release. Six pre-registered findings, reproducible from open source.
Endpoint liveness
85.4% of 2,974 FHIR-REST hosts serve a parseable CapabilityStatement. 81.6% publish valid SMART .well-known.
NPI & taxonomy
10.86M NPIs checked. 3.49% are deactivated in NPPES but live in NDH. Two specialty code systems, no cross-walk.
Temporal staleness
meta.lastUpdated on the NPD bulk files is a release-day stamp. 30- and 90-day compliance cadence is not measurable from these files.