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CMS Opt Out

CMS Opt Out Affidavits

Centers for Medicare & Medicaid Services (CMS) · Tier-2 · profile-enrichment (renders on matched profiles)

Research-only

The CMS Opt Out Affidavits file lists physicians and practitioners who have filed an affidavit opting out of Medicare under the Balanced Budget Act of 1997 §4507. Each row carries name, specialty, address, and opt-out effective/end dates. NPI is present where CMS published one; older affidavits are stored name-keyed, never with a fabricated NPI.

What Fonteum uses it for

How this source shows up on Fonteum.

Per-practitioner Medicare opt-out status, available via the read API and the dataset page. The NPI -> entity-graph link is a separate, gated follow-up — this source stamps no entity_id — so opt-out status does not yet render on individual provider profiles.

What this source does NOT mean

An opt-out affidavit is a Medicare enrollment election — the practitioner has chosen to privately contract rather than bill Medicare. It does not indicate quality, outcomes, or any disciplinary status, and it is not a Fonteum assessment of the provider.

What this dataset answers

Research and data questions this source supports.

  • Check whether a physician or practitioner has filed an affidavit opting out of Medicare, with the opt-out effective and end dates.
  • Build a network-integrity check that flags opted-out practitioners before routing Medicare referrals.
  • Research the distribution of Medicare opt-out by specialty and state over time.
  • Power a provider-data API that returns Medicare opt-out status per NPI where published.

Dataset size: 56,117 opt-out affidavits (2026-06-14 snapshot)

Fields used

Per-field display contract.

Fields listed below show their configured `display_allowed` flag from the §94 provenance schema. Fields marked write-locked are captured for audit and are not rendered on profile pages.

Research-only — never on profiles

7 fields
npiNPI (where published; null on older affidavits)
first_nameFirst name
last_nameLast name
specialtySpecialty
optout_effective_dateOpt-out effective date
optout_end_dateOpt-out end date
state_codeState
Limitations

What we can’t infer from this source.

  • Opt-out status is a Medicare enrollment election, not a quality or disciplinary signal.
  • NPI is absent on older name-keyed affidavits; those rows are stored name-keyed and never with a fabricated NPI.
  • NPI-keyed where present, but the entity-graph cross-link is deferred — opt-out status does not render on individual provider profiles yet.
  • Snapshot-based: affidavits filed after the selected artifact's observation date may be absent; no future pull is promised.
Source metadata

Authority, license, publisher cadence.

Authority

Centers for Medicare & Medicaid Services (CMS)

Tier

Tier-2 · profile-enrichment (renders on matched profiles)

Publisher / configured cadence

Declared or configured cadence: Monthly — CMS republishes the full current list under a fresh release-dated path. Not evidence of the latest loaded source date.

License

U.S. government public-domain works. Free to use with attribution; explicit redistribution rights. License ↗

Attribution requirement

Source: Centers for Medicare & Medicaid Services (CMS) — Opt Out Affidavits · Snapshot {YYYY-MM-DD}

ToS & usage notes

What the source allows.

U.S. government public-domain works. CMS publishes the Opt Out Affidavits file as a no-auth bulk CSV at data.cms.gov with explicit redistribution rights. Statutory basis: Balanced Budget Act of 1997 §4507. Snapshot and attestation fields must be read from the specific artifact; no provenance fact currently links deterministically to a signature.

Sample provenance

What a single field looks like in the graph.

This worked example shows the provenance shape used when a surfaced field has populated source, last-checked, display-rule, and confidence metadata. Individual fields may omit unavailable values.

Field

Medicare opt-out (research-only)

Sample value

NPI 1234567890 · Internal Medicine · Effective 2024-01-01 · End 2026-01-01

Provenance line

Source: CMS Opt Out Affidavits · Snapshot 2026-06-14 · Methodology cms-opt-out/v1 · Display rule: per-practitioner opt-out — read API + dataset page; profile rendering deferred with the entity-graph link

How to access

Official API, bulk download, and Fonteum endpoints.

Frequently asked

Common questions about CMS Opt Out.

What is the CMS Opt Out Affidavits file?
It lists physicians and practitioners who have filed an affidavit opting out of Medicare under the Balanced Budget Act of 1997 §4507. Each row carries name, specialty, address, and opt-out effective and end dates. NPI is present where CMS published one.
What does opting out of Medicare mean?
A provider who opts out has elected to privately contract with patients rather than bill Medicare for covered services. It is a Medicare enrollment election, not a disciplinary action or a quality signal.
Why do some rows have no NPI?
Older affidavits predate consistent NPI publication. Those rows are stored name-keyed — Fonteum never fabricates an NPI to fill the gap. The entity-graph cross-link is deferred for all rows.
Where is the data published and how often?
CMS republishes the full current list monthly at data.cms.gov as a no-auth bulk CSV. Fonteum resolves the live CSV by the stable dataset UUID and attests each snapshot. As of the 2026-06-14 snapshot, Fonteum holds 56,117 affidavits.
Does opt-out status render on provider profiles?
Not yet. Opt-out status is available via the read API and the dataset page, but the NPI → entity-graph link is deferred, so it does not yet render on individual provider profiles.
Related

Related sources in the graph

See also
  • /sources → The generated source-catalog subset — documented datasets Fonteum cites.
  • /data-provenance → The provider graph — pipeline diagram, source-family clusters, field-level provenance examples, display rules.
  • /methodology → Documented sourcing, publisher cadence, observed freshness, and corrections policy.
  • /editorial-policy → Independence, sourcing, conflicts, corrections, retractions.

What’s on file, by the numbers

Platform snapshot · 2026-08-11

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
73fresh 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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