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 or emergent situations.
- Scenario D: auth was obtained but the 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.
Scenarios A and D: corrected claim or appeal with the 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 G1 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 to 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
Writing the appeal
Structure the appeal letter around the seven-part anatomy from the master appeal guide. Every part matters, and the specifics for this denial are below.
Provider and practice information
Open with the identifiers the payer needs to locate the claim.
- Provider's full name and credentials
- Practice or facility name, NPI, and Tax ID
- Provider's NPI and Tax ID
- Contact information
Always include this on your office letterhead.
Accurate patient and claim details
- Patient name, DOB, and member ID
- Claim number, dates of service, and the original denial date
- CPT/HCPCS and ICD codes
These are what payer staff use to locate the claim. The member ID is the identifier they reach for first.
Denial reference and appeal purpose
State the exact CARC code and any RARC codes (not every denial includes one). Quote the payer's stated denial reason verbatim from the EOB or ERA. Do not risk getting the appeal denied before the supporting documentation is even reviewed by arguing the wrong denial reason.
Authorization argument
This needs to be grounded in facts. Explain why the denial is incorrect. Structure your appeal letter around the clinical documentation for clinical denials. For policy disputes, contract disputes, or fee schedule disagreements, structure your appeal letter to refer to those policies or agreements. Name the specific policy or contract term, and state why and how the policy or contract does not support the denial. For Medicare claims, cite the applicable LCD or NCD.
Supporting evidence
Attach numbered exhibits. Clearly identify each item:
- The EOB or remittance advice showing the denial
- Progress notes or operative reports
- Prior auth confirmations
- Clearinghouse batch transmission report with timestamp
- AMA CPT coding guidelines
- The payer's own medical policy
Explicit request for reconsideration
Clearly state what you are requesting: reconsideration, reprocessing, or payment at the contracted rate. Vague phrases like "please review" give the payer room to close the appeal without action.
Signature and credentials
Sign with a named person's full name, credentials, NPI where applicable, and direct contact information. For medical-necessity appeals, a clinician's signature carries the most weight. A named, reachable signer makes follow-up easier and signals the appeal was reviewed by someone accountable.
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
Prior authorization appeal letter template
Download the fillable Word template. Every bracketed field is a click-and-type control, so you can complete the letter, edit anything you need, and save it onto your own letterhead. Structured for CARC 197 denials, covering retroactive authorization requests, payer processing errors, and emergency exception scenarios.
Download the Word template