Payer-to-payer API

CMS-0057-F payer-to-payer API — sandbox overview

Under the CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F), impacted payers — Medicare Advantage organizations, Medicaid and CHIP fee-for-service programs, Medicaid and CHIP managed care plans, and QHP issuers on the Federally-Facilitated Exchanges — are required to implement a FHIR-based payer-to-payer API by January 1, 2027.

The API enables the bulk exchange of a member's clinical and administrative data between a member's previous payer and current (or concurrent) payer, with member opt-in consent, to improve care continuity and reduce duplicative data collection.

Data available

UHC payer-to-payer API includes 5 years of historical data that includes the following data:

  • USCDI v3 / US Core 6.1.0 clinical data
  • Claims and encounter data (excluding cost/provider remittance)
  • Prior authorization decisions (active and those decided within the prior 1 year, excluding drugs)

Technical foundation

Our sandbox is built to the following HL7® FHIR® Implementation Guides aligned with CMS-0057-F:

Capability Implementation guide

Clinical & administrative data exchange

Da Vinci PDex v2.1.0

Member identification

Da Vinci PDex $member-match operation

Prior authorization history

Da Vinci PAS v2.1.0 (read)

Underlying data model

US Core 6.1.0 / USCDI v3

Bulk data

FHIR Bulk Data Access (Flat FHIR) v2.0.0

Sandbox capabilities

The sandbox environment provides:

  • Synthetic member test data spanning multiple coverage scenarios (MA, Medicaid MCO, QHP)
  • $member-match endpoint to validate member matching workflows before production exchange
  • Bulk $davinci-data-export operation supporting asynchronous Group-level export of Patient, Coverage, ExplanationOfBenefit, Claim, and clinical USCDI v3 resources
  • PAS read endpoints for prior authorization history retrieval
  • Consent simulation to test opt-in/opt-out handling
  • Sample OAuth 2.0 registration and test credentials issued upon onboarding

Base URL

  • Sandbox URL is test.flex-nonprod.optum.com

Who should use the sandbox

This environment is intended for payer technical teams, vendors, and integration partners preparing for CMS-0057-F compliance who want to:

  • Validate their client implementation against PDex v2.1.0 and the $davinci-data-export operation
  • Test individual api as well as single and multiple bulk export request/response flows and async job polling
  • Confirm consent and member-matching error handling
  • Perform end-to-end connectivity, security, and conformance testing before production cutover

UHC payer-to-payer endpoints

Individual API endpoints:

  • https://[base]/fhir/R4/Patient
  • https://[base]/fhir/R4/Coverage
  • https://[base]/fhir/R4/Procedure
  • https://[base]/fhir/R4/Immunization
  • https://[base]/fhir/R4/Observation
  • https://[base]/fhir/R4/Encounter1
  • https://[base]/fhir/R4/Condition
  • https://[base]/fhir/R4/MedicationRequest
  • https://[base]/fhir/R4/Medication
  • https://[base]/fhir/R4/MedicationDispense
  • https://[base]/fhir/R4/ExplanationofBenefit2

Bulk single member endpoints:

  • https://[base]/fhir/R4/Patient/$member-match
  • https://[base]/fhir/R4/Patient/$export

Bulk multiple members endpoint:

  • https://[base]/fhir/R4/Group/$bulk-member-match
  • https://[base]/fhir/R4/Group/$davinci-data-export

Getting Started

  1. Request access through the developer portal and complete the payer attestation form.
  2. Register your client and receive OAuth 2.0 sandbox credentials.
  3. Review our Implementation Guide pack (PDex 2.1.0, PAS 2.1.0, US Core 6.1.0, Bulk Data 2.0.0).
  4. Run conformance tests using the provided synthetic member dataset.
  5. Schedule a pilot phase with our integration team for joint testing by emailing uhc_p2p_ops@uhc.com.
  6. Upon successful sandbox testing, production onboarding will be required.