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Fonteum 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.

Source file
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Published
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Retrieved
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Snapshot
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Data as of
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Last updated: 2026-07-11Reviewed 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 can group records when participating sources publish a shared identifier. Unmatched records remain source-local, and provenance fields vary by source.

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.

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What’s on file, by the numbers

Platform snapshot · 2026-08-23

13.4Mproviders & companiesProviders, organizations, owners, and facilities on file
26.2Msource-linked factsSource-linked field facts in the dated platform snapshot
90sources with dataDistinct snapshot source IDs with at least one positive record count
70fresh sourcesDistinct source IDs whose latest positive-data snapshot falls within the preceding 45 days
111sources integratedActive registry rows; integration does not establish a load
13state Medicaid jurisdictionsDistinct states represented in the state-exclusions serving table

Integrated, with-data, and fresh-observation counts are separate. No platform-wide source-completeness count is published. Completeness is source-specific and must be evaluated against the named source's expected scope. State coverage is a separate jurisdiction measure.

Source authority is record-specific

Use the issuer named on the record.

Fonteum spans federal, state, and global public publishers. A source page or returned record identifies its issuer and dataset where that metadata is available. A platform registry count does not assign every page to one authority or establish loaded, fresh, or complete coverage.

Browse source records and their stated limitations →

Reproducible by design

Inspect the evidence each published figure actually supplies.

Source and date

Research pages expose the named public file and observation date where those fields are available. Source-file SHA-256 coverage is separate; facts do not currently link deterministically to signatures.

Available derivation

Studies with a retained release and committed derivation link the SQL or method used. Other studies state the evidence and reproduction limits they actually have.

Daily observations

Dated table row-count observations can detect local drift. They do not imply that an upstream publisher released or Fonteum ingested new data that day.

Named medical review

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

Read the full provenance and attestation methodology →

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