Composite resolution— v2.

Inputs

6 federal source families.

A returned block identifies one of these declared sources. Not every source is loaded or NPI-keyed, and a listed source can produce a null block. Fonteum does not use fuzzy name or address matching to fill a missing NPI join.

Join key

NPI joins only where the source publishes it.

The National Provider Identifier is a federally assigned 10-digit administrative identifier. An organization can hold more than one NPI for enumerated subparts, and some listed sources publish no NPI. Fonteumdoes not perform name-based, address-based, or specialty-based matching to bridge these composite blocks — an NPI join is exact or the block remains null.

If NPPES has no record for the requested NPI, the endpoint returns 404 even when other source families may carry a row under the same number. NPPES is the registry of record.

Conflict resolution

Disagreements stay visible.

When the same field appears in more than one source (for example, specialty in NPPES vs. PECOS), the composite response surfaces both values on their per-source blocks. Fonteum does not silently pick one. The reader sees the NPPES value under sources.nppes.data, the PECOS value under sources.pecos.data, and the available provenance object on each block reports the source, snapshot, and confidence fields supplied by that response; fields can be null.

Confidence scoring

The 0 – 1 scale.

• 1.0 — source returned the field with no parse warnings.
• 0.9 — field present but normalized (case-folded, whitespace trimmed, zip truncated).
• 0.7 — field inferred from a related field (primary taxonomy from a non-primary one).
• 0.0 — field absent or source not yet ingested (data_availability flags say so).

The composite block exposes field_confidence_min— the minimum confidence across all returned source blocks. A caller can index on it to decide whether to trust the joined record without re-parsing every per-source provenance object.

Composite flags

Why active_and_clean is tri-state.

This legacy-named field is true only when NPPES registry status is Active and the unified OIG LEIE, SAM.gov, and state Medicaid exclusion screen returns no match while its coverage is current and reconciled. It is false when the registry is inactive or an affirmative exclusion is present. It is nullwhen exclusion coverage is stale or cannot be reconciled to a comparable attested source artifact. A null result is indeterminate and is not a clearance. PECOS enrollment deactivation is not evaluated because the public serving table does not expose that field.

Limitations

What this endpoint does not do.

• Does not provide universal historical replay. A block represents the loaded response available to this endpoint and can lag the publisher; source dates vary and can be null.
• Does not return Open Payments line items. When the NPI-keyed ingest lands the block will surface program-year aggregates only.
• Does not return risk signals or anomaly flags. Risk scoring is a separate methodology on a separate roadmap wave.
• Does not verify provider credentials. Fonteum publishes what CMS, OIG, and SAM.gov publish.

Versioning

Pinned at v2.

This page is the canonical methodology pin for the response shape the endpoint emits. Version 2 makes active_and_clean tri-state so stale or unreconciled exclusion coverage cannot appear as a clean result. The canonical page at https://fonteum.com/methodology/composite visibly carries the current v2 contract; the prior v1 semantics are recorded in the public methodology and corrections log. Future breaking changes — renaming a top-level key, dropping a source family, or changing the meaning of active_and_clean— require another major version. Additive changes (a new optional field on the composite block, a new source family added to the join) do not bump the version.

Related

Where this methodology is used.

• Platform methodology — how every layer of the record pipeline works, from capture to signing.
• API reference — the /api/v1/npi/{npi} endpoint contract that pins this page in its X-Fonteum-Methodology header.
• Trust center — audit pack, corrections process, and the signing chain behind each block.