CMS
Open Payments →Financial transfers from manufacturers to physicians and teaching hospitals.
Medicare Opt Out Affidavits
Physicians and practitioners who filed an affidavit opting out of Medicare — name, specialty, and opt-out effective/end dates. NPI is present where CMS published one; entity-graph linkage is deferred. Source:
FHIR Practitioner · Sample record
What a record looks like in the API response.
{
"resourceType": "Practitioner",
"id": "optout-example",
"_source": "cms-opt-out-affidavits",
"_methodology": "cms-opt-out/v1",
"extension": [{ "url": "optOutEffectiveDate", "valueDate": "2024-01-01" }]
}Every record carries _source, _methodology, a snapshot date, and a confidence tier. All fourteen provenance fields survive export and API delivery.
curl -H "Authorization: Bearer $FONTEUM_KEY" \ "https://api.fonteum.com/fhir/r4/Practitioner?_source=opt-out" \ | jq '._source, ._methodology, .meta.tag'
Dataset facts
| Field | Value |
|---|---|
| Agency | |
| Category | Provider performance |
| Records | |
| Temporal coverage | 1998–2026 |
| Refresh cadence | Monthly |
| Freshness SLA | Within 24h of monthly CMS release |
| Last synced | 2026-06-14Updated 2026-06-14 |
| FHIR resource | Practitioner |
| Methodology | cms-opt-out/v1 |
| Measured | Practitioner name, specialty, opt-out effective and end dates per affidavit |
| Upstream source | data.cms.gov → |
Get access
How to reach this dataset.
API access is operator-approved during the pilot. Reviewed within one business day. No charge during the pilot period.
Related · Provider performance
CMS
QPP Individual Scores →Individual clinician performance scores from the Quality Payment Program.
CMS
PECOS Ordering & Referring →Medicare enrollment status for providers eligible to order and refer services.