CARC 96 is one of the broadest denial codes on the books. On its own, it only tells you the charge is non-covered. It does not tell you why. The actual reason lives in the remark code paired with it, and reading that remark code correctly is the difference between a two-minute write-off and a winnable appeal. This guide walks through how to separate the two, and how to protect revenue when an Advance Beneficiary Notice (ABN) is or is not already on file.
Read the paired remark code first
CARC 96 tells you the charge is non-covered. It does not tell you why. The code's own usage rules require at least one accompanying remark code on the 835 remittance, and that remark code is where the real reason for the denial lives.
Note: not every payer follows that rule. If the remark code is missing, contact the payer and get the specific reason before you take any other action.
Once you have the reason, sort the denial into one of two buckets:
- True exclusion: the plan document specifically excludes this category of service. Cosmetic procedures, services outside the benefit period, or a benefit the member's specific plan does not offer. An appeal cannot overturn plan design.
- Fixable error: the service is a covered benefit, but the claim was missing a prior authorization, used an outdated or incorrect code, was billed under the wrong place of service, or the diagnosis did not support medical necessity as coded. These are correctable or appealable.
Note: denials labeled experimental or investigational deserve a closer look before they go in either bucket. Payers apply those labels inconsistently, and they are overturned on appeal and external review often enough that they should never be treated as automatic write-offs.
Confusing these buckets wastes appeal effort on unwinnable cases and, worse, causes practices to write off charges that were recoverable with a simple correction.
Not covered by policy vs. not medically necessary
A medical necessity denial should arrive as CARC 50, but payers do not always keep the two separated, and necessity-driven denials show up under CARC 96 more often than they should. The distinction matters because the two require entirely different responses. A benefit exclusion is plan design — it has nothing to do with the patient's clinical presentation and cannot be argued away with better documentation. A medical necessity denial means the payer's clinical criteria were not met by the documentation submitted, and that is exactly the kind of denial documentation can fix.
| Scenario | What it means | Best action |
|---|---|---|
| Plan excludes the service category | Not a covered benefit for this member | Write off, or bill the patient if a signed ABN or plan exclusion notice is on file |
| Missing prior authorization | Service is covered, but the authorization step was skipped | Request retroactive authorization if the payer allows it, then appeal |
| Medical necessity criteria not met on paper | Service is covered when criteria are documented, and the record may support it | Appeal with clinical documentation addressing each unmet criterion |
| Member has a supplemental rider | Coverage exists under an add-on benefit not checked at intake | Verify eligibility again, resubmit with corrected coverage information |
The role of the ABN and patient responsibility
An Advance Beneficiary Notice (ABN) is the Medicare tool that shifts financial liability to the patient when you reasonably expect a service to be denied as not medically necessary or non-covered. Most commercial payers have an equivalent, usually called a waiver of liability or notice of non-coverage, and the same logic applies: the patient agrees in writing, before the service is rendered, to accept financial responsibility. A properly executed ABN lists the specific service, and the specific reason coverage is expected to be denied. Without one on file, many non-covered denials become a write-off even when the exclusion itself was legitimate.
Before you appeal, or bill the patient, pull the following:
- The signed and dated ABN, specific to the service and the reason for expected denial, completed before the service was rendered
- Modifier GA (waiver on file), GY (statutorily excluded, no ABN required), or GZ (expected denial, no ABN obtained), applied consistently with what actually happened
- Eligibility verification records showing what was confirmed at intake versus what the payer later determined
- The prior authorization request and response, if the denial stems from a missing or expired authorization
- Clinical documentation addressing the payer's specific medical necessity criteria, when the denial is a necessity issue rather than a hard exclusion
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.
Coverage or clinical 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.
Non-covered service appeal letter template
Pre-built appeal letter for CARC 96 denials, with a decision checklist for distinguishing a true exclusion from a fixable coverage error.
Browse appeal templates →