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  1. Fonteum
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  5. Entity Resolution
Healthcare Data GlossaryTech

Entity Resolution: Definition and Healthcare Context

Full name: Provider Entity Resolution

Entity resolution is the process of determining when records across different datasets refer to the same real-world entity — a single provider, facility, or organization. In health care data, the same physician can appear under different name spellings, addresses, and identifiers across NPPES, PECOS, Open Payments, and exclusion lists. Entity resolution links those records to one resolved identity, usually anchored on a stable key such as the NPI for individuals or the CMS Certification Number for facilities, so a fact in one source can be joined to a fact in another.

Last updated: 2026-06-17Reviewed by: Dr. Jennifer Montecillo, MD — Gullas College of Medicine, 2019. Non-practicing medical reviewer.

How it’s used

  • CMS NPPES NPI Registry: the NPI is the deterministic anchor key that joins individual-provider records across federal datasets.
  • CMS Provider of Services (POS) File: the CCN is the facility identity backbone that links Care Compare, HCRIS, and ownership data.
  • CMS Open Payments: physician payment records are resolved to NPPES identities so payments can be read against a provider's full profile.
  • Fonteum's resolution layer produces one record per provider, with each linked field carrying provenance back to the source that asserted it.

Frequently asked questions

What is entity resolution?
Entity resolution determines when two or more records — often from different datasets — describe the same real-world person, facility, or organization, then links them into a single resolved identity.
Why is entity resolution hard in healthcare data?
The same provider appears with different name spellings, addresses, and identifiers across NPPES, PECOS, Open Payments, and exclusion lists, so matching requires more than an exact string comparison.
What key does Fonteum resolve provider records on?
Individual providers are anchored on the 10-digit NPI; certified facilities are anchored on the 6-digit CMS Certification Number, which serves as the join key across CMS facility datasets.

Related terms

  • NPI Number
  • CCN
  • NPPES
  • UEI
  • Provenance
  • Bitemporal

Explore in Fonteum

How Fonteum sources, resolves, and publishes data tied to this term.

  • PlatformEntity graph — one resolved record per provider
  • PlatformCross-source reconciliation
  • PlatformMethodology

Authoritative sources

  • NPPES NPI Registry — official↗
  • CMS NPPES bulk data download↗
← All glossary terms

The substrate, by the numbers

9.2Mgraph entitiesProviders, organizations, owners, and facilities
15.7Mlinked identifiersNPIs, CCNs, LEIs and more, resolved to entities
5Mgraph edgesSource-attested relationships between entities
44federal source familiesDistinct CMS, OIG, HRSA, FDA and peer datasets
35dataset pagesCitable, downloadable /data catalog pages
65reproducible studiesEach shipping the SQL behind its figures

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.

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

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