Da Vinci PAS (Prior Authorization Support)
The Da Vinci Prior Authorization Support (PAS) implementation guide defines a FHIR-based workflow for submitting and processing prior authorization requests electronically. It modernizes the prior auth process by replacing phone, fax, and EDI 278 transactions with real-time FHIR API calls.
The $submit Operation
PAS defines the $submit operation as the primary mechanism for prior auth:
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Provider EHR constructs a PAS request Bundle containing:
- Claim resource (with use = "preauthorization")
- Patient resource
- Coverage resource
- Supporting clinical information (Condition, Observation, DocumentReference)
- Practitioner and Organization references
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EHR submits the Bundle via POST to the payer's PAS endpoint
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Payer responds with a ClaimResponse containing:
- Approved — Authorization granted with approval number and validity period
- Denied — With specific, actionable denial reasons
- Pended — More information needed; payer may request additional documentation
- Partial — Some items approved, others denied or pended
How PAS Replaces EDI 278
| Feature | EDI 278 | Da Vinci PAS |
|---|---|---|
| Format | X12 fixed segments | FHIR JSON/XML |
| Interaction | Batch or real-time via VAN | RESTful API over HTTPS |
| Response time | Hours to days | Seconds to minutes |
| Clinical data | Limited attachment support | Rich Bundle with full clinical context |
| Denial reasons | Generic codes | Specific, actionable reasons |
| Developer experience | Specialized X12 expertise | Standard web development skills |
The CRD/DTR/PAS Workflow
PAS is part of a three-IG workflow designed to streamline prior auth from the point of care:
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CRD (Coverage Requirements Discovery) — At the moment a provider orders a service, CDS Hooks fire to the payer → payer responds with coverage requirements and whether PA is needed
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DTR (Documentation Templates and Rules) — If documentation is required, payer sends SMART on FHIR questionnaires → forms auto-populate from EHR data → provider completes remaining fields
-
PAS (Prior Authorization Support) — Completed request is submitted to the payer via $submit → immediate or near-immediate response
CMS Mandate
Under CMS-0057-F, impacted payers must:
- Accept FHIR-based prior auth requests by January 1, 2026 (certain provisions)
- Full compliance by January 1, 2027
- Respond to urgent requests within 72 hours
- Respond to standard requests within 7 calendar days
- Provide specific reasons for denials
