Construct and transmit an X12 278 prior authorization request and handle synchronous approve, deny, and pend responses

Verified steps

1. Identify the applicable implementation guide: the HIPAA-mandated standard for prior authorization requests is X12 278 version 005010X217; obtain the guide from x12.org/products or your clearinghouse companion guide.
2. Build the request transaction: Loop 2000A (utilization management organization), Loop 2000B (requester), Loop 2000C (subscriber), Loop 2000D (patient if different from subscriber), Loop 2000E (service review — populate UM01 request category code, UM02 certification type, SV1/SV2 service line with quantity and procedure code).
3. Include Loop 2010EA (attending provider NPI) and any required diagnosis codes in the HI segment using the ICD-10-CM qualifier; missing or wrong qualifier is the most common rejection reason.
4. Submit via your clearinghouse (Availity, Optum, or Stedi); a synchronous 278 response is returned if the payer supports real-time adjudication — check HCR01 (action code): A1=approved, A3=modified, A4=denied, A6=modified/approved.
5. For a pend response (HCR01=A2), store the payer-assigned certification number (REF*CE) and poll the payer or clearinghouse status endpoint using that reference until a final disposition is received.
6. Record the approved service type, approved units, and effective/expiration dates from the response REF and DTP segments for downstream claim attachment and billing.