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Built on the authoritative federal record

The primary sources, named on every page.

These are the federal agencies whose public datasets Fonteum ingests and attributes — the issuing authorities, not customers or partners. Every figure on the site links back to one of them.

  • CMS
  • HHS-OIG
  • HRSA
  • FDA
  • NLM
  • NUCC
  • Census
  • BLS
  • BEA

See the full source registry, with license and refresh cadence for each →

Reproducible by design

Every figure traces to its federal source.

14-tuple provenance

Every rendered fact ties to a source URL, dataset ID, snapshot date, row key, and SHA-256 — the full chain-of-custody record.

Reproducible SQL

Each study ships the exact query behind its figures, run against the cited federal snapshot. Re-run it yourself.

Daily reconciliation

Published counts are reconciled against the upstream federal datasets on a daily cadence, with drift logged.

Named medical review

Reviewed by Jennifer Montecillo, MD, medical reviewer. Non-practicing medical reviewer.

Read the full provenance and attestation methodology →

Two doors

Use the free API and open data

Query providers, facilities, sanctions, and quality scores — each field carrying its federal source. Self-serve, no call to start.

Explore the API →Browse the data catalog →

Talk to us

Managed pilots, enterprise terms, and audit-ready, signed attestation packages for compliance, risk, and research teams.

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Reviewed by Jennifer Montecillo, MD, medical reviewer. Non-practicing medical reviewer.

© 2026 Fonteum LLC. All rights reserved.

The U.S. healthcare graph AI can cite — every fact carries its source.

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The substrate, by the numbers

9.2Mgraph entitiesProviders, organizations, owners, and facilities
13.3Mlinked identifiersNPIs, CCNs, LEIs and more, resolved to entities
4.7Mgraph edgesSource-attested relationships between entities
44federal source familiesDistinct CMS, OIG, HRSA, FDA and peer datasets
35dataset pagesCitable, downloadable /data catalog pages
52reproducible studiesEach shipping the SQL behind its figures

Trust → Integrity → Chain

Attestation chain head.

Every snapshot Fonteum publishes is SHA-256 hashed at write time and appended to a Certificate-Transparency-style log. The head of that log — the most recent attestation — is published below. Once the per-snapshot previous_link_hash backfill lands under §sprint3-attestation-chain, every row will additionally chain backwards to the prior row, making any tampering detectable by a single recomputation.

Current head
snapshot_id
193
source_id
cms-ncci-ptp-edits
snapshot_date
2026-06-15
content_hash (SHA-256)
e46364aee887a1c9da3ef9f5440500dd054b0717d3e69de244b190f093b35d93
attested_at
2026-06-15T11:40:56.292678+00:00
previous_link_hash
(deferred — §sprint3-attestation-chain)
signing_key
(STH signing key publishes with first signed tree head)

Total attestations on file: 148

Witness co-signatures — snapshot 193

No witness signatures on file for this snapshot.

Verify this snapshot programmatically: /api/attestation/verify/193

How the chain works

  1. Each upstream archive is downloaded, SHA-256 hashed, and written to snapshot_attestations with the source archive URL preserved verbatim.
  2. Each new row carries a previous_link_hashfield set to the prior row's content_hash (or all-zero for the first row in a source family). Tampering with any historical row breaks every downstream link.
  3. A periodic STH (Signed Tree Head) seals the chain head with Fonteum's chain-signing public key. Verifiers fetch the STH, walk the chain backwards, and confirm every link.
/verify — re-hash any attested snapshot →/trust/integrity — full attestation index →/docs/cache — 90-day source mirror →

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