Download or query the Medicare Opt-Out Affidavits dataset from https://data.cms.gov/provider-characteristics/medicare-provider-supplier-enrollment/opt-out-affidavits — the dataset (identifier 7yuw-754z) is updated monthly from PECOS.
Access the data via the CMS data API using the dataset identifier; query parameters support filtering by NPI, provider name, and specialty to retrieve specific providers or subsets.
Key fields to extract: NPI, first/last name, specialty, address, optout_effective_date, and optout_end_date; a null optout_end_date indicates the opt-out is currently active.
Integrate opt-out checking into your credentialing and claims workflows: flag any provider whose NPI appears in the active opt-out list, as Medicare will not reimburse for services rendered by opted-out providers except in emergencies.
Schedule monthly refresh of your local opt-out list copy to align with CMS update cadence; do not rely on a stale snapshot for compliance decisions.
Distinguish between opted-out providers (who have affirmatively filed an affidavit) and non-participating providers (who accept Medicare assignment at reduced rates) — they are different enrollment statuses with different billing implications.
Known gotchas
An opted-out provider can only be paid by Medicare in a genuine medical emergency; billing Medicare for non-emergency services rendered by an opted-out provider results in claim denial and potential fraud liability.
The opt-out affidavit period is two years and renews automatically unless the provider withdraws; optout_end_date in the dataset may reflect the end of the affidavit period, not the actual termination of opt-out status — check current status, not just the date.
Opted-out providers may use private contracts with patients — your credentialing workflow must capture whether a private contract is in place before any Medicare billing attempt is made.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp