How to Appeal a Prior Authorization Denial

Prior authorization denials are process failures — either the authorization wasn't obtained, it was obtained for the wrong service or date range, or it wasn't referenced correctly on the claim. The good news: many CARC 197 denials are recoverable once you understand exactly which scenario you're dealing with.

Determine Which Scenario You're In

Before doing anything else, confirm what actually happened:

• Scenario A: Auth was obtained but not submitted on the claim. This is purely administrative — the auth existed but the auth number wasn't on the claim. Corrected claim resubmission with the auth number typically resolves it.
• Scenario B: Auth was obtained for the wrong date or service code. The auth references a different date of service or a different procedure. This may require a retroactive auth request or a corrected claim if the service falls within the auth window.
• Scenario C: Auth was never obtained. The service was rendered without authorization. This is the hardest scenario — but retroactive authorization is sometimes available for urgent/emergent situations.
• Scenario D: Auth was obtained but payer lost or misapplied it. Payer processing error — appeal with the auth number, date obtained, and the name of the representative who issued it if you have it.

Scenario A and D: Corrected Claim or Appeal with Auth Number

If the auth was obtained but wasn't on the claim, or the payer failed to match it, resubmit the claim with the authorization number in the appropriate field (Loop 2300, REF segment, reference identification qualifier PA for prior authorization). Include the auth number, approval date, and approving payer representative if documented.

Scenario B: Retroactive Authorization

Contact the payer's authorization department — not the claims department — and request a retroactive authorization review. Most payers have a formal retroactive auth process, though they may limit it to 30–90 days post-service. When requesting retroactive auth:

• Provide the date of service, procedure code, and the original authorization number if one exists
• Explain why the auth was not obtained in advance (urgent clinical situation, payer error, eligibility confusion)
• Include clinical documentation supporting medical necessity

Scenario C: Emergency or Urgent Care Exception

If the service was rendered in an emergency situation where obtaining prior authorization was not clinically feasible, most payers — and federal and state regulations — provide for after-the-fact authorization. Document:

• The clinical urgency that made advance authorization impossible
• The date and time the service was rendered and when the payer was notified
• Any emergency department records, admission notes, or physician attestation of urgency

Prevention: Stop CARC 197 Before It Starts

Prior authorization denials are almost entirely preventable with a consistent authorization workflow:

• Maintain an updated list of services that require auth for each payer in your system
• Verify authorization requirements at every eligibility check — payers change their auth lists regularly
• Confirm the auth covers the specific CPT code and date range before the service is rendered
• Document the auth number, approval date, and approving representative in the patient account at time of authorization
• Build a pre-billing audit step that flags any claim requiring auth and verifies the auth number is present before submission