CARC & RARC
Intelligence Center

Contractual Obligation

The adjustment represents the amount that is contractually written off. This is not billable to the patient — it is the difference between billed charges and the payer allowed amount per the provider contract.

Patient Responsibility

The adjustment represents an amount the patient owes — deductible, coinsurance, copay, or non-covered services. This amount should be billed to the patient per their plan design.

Other Adjustment

The adjustment is for a reason not covered by CO or PR. Often used for informational adjustments, coordination of benefits, or payer-specific adjustments that are neither contractual nor patient responsibility.

Payer-Initiated

The payer initiated the reduction or adjustment. Used when the payer reduces payment based on their own policy or medical review, rather than a contractual adjustment or patient responsibility.

Claim/service lacks information or has submission/billing error.

The claim is missing a required data element or contains invalid information. The payer cannot proce...

These are non-covered services because this is not deemed a "medical necessity" by the payer.

The payer determined the service does not meet their medical necessity criteria based on the diagnos...

Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.

CO-45 is NOT a denial — it is a contractual adjustment. The difference between your billed charge an...

Precertification/authorization/notification absent.

The payer required prior authorization before the service was rendered, and no valid authorization w...

The diagnosis is inconsistent with the procedure.

The ICD-10 diagnosis code submitted does not support medical necessity for the procedure billed. The...

The time limit for filing has expired.

The claim was submitted after the payer filing deadline. Most payers will permanently deny claims su...

Exact duplicate claim/service.

The payer received and is currently processing — or has already processed — an identical claim. Resu...

Deductible amount — patient responsibility.

The patient has not yet met their annual deductible. This amount is the patient financial obligation...

The service is inconsistent with the modifier used.

A modifier on the claim does not match the procedure code, clinical context, or payer policy. The pa...

The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated.

This procedure is bundled with another code that was already paid. The payer will not pay for both u...

This care may be covered by another payer per coordination of benefits.

The payer believes another insurance plan should be billed first (or also). COB rules determine paye...

Missing/incomplete/invalid referring provider primary identifier.

The NPI or other identifier for the referring provider is missing or invalid. Required for most paye...

Missing/incomplete/invalid rendering provider primary identifier.

The rendering provider NPI is missing or invalid. Every claim must include a valid rendering NPI....

Missing/incomplete/invalid procedure code(s).

A required procedure code (CPT/HCPCS) is missing, invalid, or cannot be identified from the claim as...

Missing/incomplete/invalid patient identifier.

Patient identification information on the claim is missing, incomplete, or does not match payer reco...

Missing/incomplete/invalid diagnosis or condition.

A required diagnosis or condition code is not present or is incomplete. Often appears alongside CO-1...

Consult plan benefit documents/guidelines for information about this decision.

The payer is directing you to review the plan benefit document for information about the coverage de...

If you do not agree with what we approved, you may appeal our decision.

This is a Medicare Remittance Advice Remark informing the provider of appeal rights. It is not a den...