Map FHIR PAS Claim resources to X12 278 prior authorization request transactions for intermediary translation

Steps

1. Review the Da Vinci PAS IG companion X12 278 mapping tables, which specify how each FHIR PAS Claim element maps to X12 278 loops, segments, and elements.
2. Map the PAS Claim header (patient, subscriber, payer, provider) to X12 278 Loop 2000A (payer), 2000B (subscriber), 2000C (dependent, if applicable), and 2000D (service provider) level segments.
3. Map Claim.item entries to X12 278 Loop 2000F (service) with UM (health care services review information) segments for service type, level of service, and facility type code.
4. Map diagnosis codes from Claim.diagnosis to X12 278 HI (health care information codes) segments using the appropriate qualifier codes for principal diagnosis and other diagnoses.
5. Map requested procedure codes, modifiers, quantities, and dates from Claim.item to X12 278 SV1/SV2 (professional/institutional service information) and DTP (date or time period) segments.
6. Validate the generated X12 278 against the applicable X12 278 implementation guide version (typically the version mandated by the payer or CMS) before submission, and map validation errors back to their FHIR Claim source elements for debugging.