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CMS Opt OutCMS Opt Out Affidavits
Centers for Medicare & Medicaid Services (CMS) · Tier-2 · profile-enrichment (renders on matched profiles)
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.
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.
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)
Per-field display contract.
Every field below has a `display_allowed` flag in the §94 provenance schema. Write-locked fields are captured to provenance for audit but never rendered on profile pages.
Research-only — never on profiles
7 fieldsWhat 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 monthly snapshot do not appear until the next pull.
Authority, license, refresh cadence.
Authority
Centers for Medicare & Medicaid Services (CMS)
Tier
Tier-2 · profile-enrichment (renders on matched profiles)
Refresh cadence
Monthly — CMS republishes the full current list under a fresh release-dated path; Fonteum resolves the live CSV by the stable dataset UUID.
License
U.S. government public-domain works. Free to use with attribution; explicit redistribution rights. License ↗
Official URL
Attribution requirement
Source: Centers for Medicare & Medicaid Services (CMS) — Opt Out Affidavits · Snapshot {YYYY-MM-DD}
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. Fonteum resolves the live release-dated CSV by the stable dataset UUID and attests each snapshot.
What a single field looks like in the graph.
A worked example. Every field surfaced from this source carries this shape of provenance line — source · last checked · display rule · confidence (when applicable).
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
Official API, bulk download, and Fonteum endpoints.
Official API / download
Fonteum surface
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.
Where this source already shows up.
Related sources in the graph
- /sources → The full source library — every dataset Fonteum cites.
- /data-provenance → The provider graph — pipeline diagram, source-family clusters, field-level provenance examples, display rules.
- /methodology → Network-wide sourcing, refresh cadence, and corrections policy.
- /editorial-policy → Independence, sourcing, conflicts, corrections, retractions.