integrate with a payer Patient Access API under the CMS interoperability rule (Da Vinci / CARIN)

Steps

1. Discover the payer's Patient Access API endpoint; CMS-regulated payers must publish their FHIR R4 base URL and SMART configuration—look for it in their developer portal or via the CMS endpoint directory.
2. Register your application with the payer's developer portal, requesting SMART scopes aligned with CARIN Blue Button IG (e.g. patient/ExplanationOfBenefit.read, patient/Coverage.read, patient/Patient.read).
3. Implement the SMART on FHIR standalone launch flow so members can authenticate with their health plan credentials and grant your app access.
4. After obtaining a token, retrieve ExplanationOfBenefit resources for claims history, Coverage for current plan details, and Patient for demographic data.
5. Handle the CARIN BB profile-specific extensions on ExplanationOfBenefit (e.g. inNetworkProvider, adjudicationCategory) when parsing claim line items.
6. For provider-facing workflows, explore the Da Vinci Payer Data Exchange (PDex) and Prior Authorization Support (PAS) IGs which use different resource types and flows.