CMS-0057-F Interoperability Sandbox

The four payer APIs of the CMS prior authorization rule, working end to end

A working model of the payer side of the CMS Interoperability and Prior Authorization final rule. All four mandated FHIR APIs are implemented end to end, driven by approximately 3,154 rules extracted from four publicly available 2026 prior authorization grids.

Final rule
CMS-0057-F
Regulation
45 CFR 156.221
API compliance date
January 1, 2027
Operational provisions
January 1, 2026
Payer
UM Dashboard
Rules explorer over the ingested PA grids, live traffic feed with the FHIR ↔ X12 drawer, Provider Access panel, and P2P Exchange.
Provider
EHR Workspace
Order entry → CDS Hooks card → DTR questionnaire → PAS Bundle submission, with pended and denial paths.
Member
Patient Portal
Coverage card, SMART scopes, and the prior authorization history generated by the payer events.
The four mandated APIs and where they live
156.221(d)Prior Authorization API (CRD → DTR → PAS)/ehr + /um Live Traffic Feed
156.221(a)Patient Access API/patient
156.221(b)Provider Access API/um Provider Access tab
156.221(c)Payer-to-Payer API ($member-match)/um P2P Exchange tab
A suggested path through the demo

The sandbox boots pre-seeded with the full rule index and a replayed demo session, so every surface has data before the first click. The steps below walk one order through all four APIs.

  1. 1/umOpen the UM dashboard. The rule index is pre-loaded; search 70553 in the Rules Explorer to see the MRI Brain rule, its Carelon routing, and its provenance back to the source PDF page.
  2. 2/ehrOpen the EHR as Jane Doe and sign the MRI Brain order. A CDS Hooks card returns with the DTR questionnaire link; complete it and submit the PAS request.
  3. 3/umBack in the UM dashboard, watch the Live Traffic Feed. Expand the FHIR ↔ X12 drawer on the X12 278 REQUEST entry to inspect the field-to-segment mapping.
  4. 4/patientOpen the patient portal as Jane Doe. The same determination appears in her prior authorization history through the Patient Access API.
  5. 5/umIn the P2P Exchange tab, run $member-match for a newly enrolled member and retrieve the prior plan PA history.
Source on GitHub · AGPL-3.0 licensed. The source for this deployment is the repository linked above.
Demonstration environment with synthetic patients. The rule data comes from publicly available BCBSIL documents (Medicare Advantage, Commercial Med-Surg, Specialty Pharmacy, Behavioral Health). This project is not affiliated with or endorsed by BCBSIL, CMS, Epic, or Availity.
Data use. This sandbox processes only synthetic patient data by default. When launched from an external EHR sandbox via SMART on FHIR, the launched Patient resource is fetched and displayed for the current browser session only. Nothing is persisted, sold, shared, or used for any secondary purpose. Access tokens live in sessionStorage and clear on tab close or when the "End session" control is used.
The Reset demo control in the UM dashboard restores the seeded baseline at any time.