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Claim Denial & Adjustment Codes Directory
Translate insurance Claim Adjustment Reason Codes (CARC). Understand whether a code represents a provider write-off, an actual claim rejection, or patient cost-sharing.
CO-45: Charge Exceeds Fee Schedule
The provider billed more than the maximum allowable rate under their network contract. The participating doctor must write off this difference; you do not owe the adjusted portion.
CO-97: Bundled or Inclusive Service
The service is considered integral to another primary procedure performed on the same date and cannot be billed separately under correct coding rules. The provider writes off the secondary charge.
CO-16: Claim Lacks Information / Missing Modifier
The claim was submitted with missing or invalid clinical documentation, unattached records, or a missing billing modifier. The provider must correct and resubmit; they cannot bill you for their filing omission.
CO-18: Duplicate Claim or Service
The provider submitted an exact copy of a claim that has already been adjudicated or paid. Insurance flags it as a duplicate to prevent paying twice. You cannot be billed for a duplicate line.
PR-1: Deductible Amount
The amount applied toward your health plan's annual deductible. Because you have not met your full deductible threshold for the calendar year, you are responsible for paying this allowable portion to the provider.
PR-2: Coinsurance Amount
Your percentage share of the allowable rate after deductible has been met (e.g. 20% coinsurance on an $180 allowed rate = $36). The provider bills you for this legitimate cost-sharing portion.
PR-3: Fixed Copayment Amount
The fixed copay specified by your health plan for an office visit, specialist consultation, or emergency department encounter (e.g., $30 copay). Usually collected at time of check-in.
PR-204: Service Not Covered Under Patient Benefit Plan
The specific service, drug, or device is completely excluded from your insurance policy's certificate of coverage. Unlike CO-45, insurance pays $0 and passes full liability to the patient.
CO-50: Not Deemed a "Medical Necessity"
The insurer's medical review team determined the procedure was not medically necessary under clinical guidelines. In-network doctors cannot bill you unless you signed an Advance Beneficiary Notice (ABN) prior to care.
OA-23: Adjusted by Prior Payer
Used when a patient has secondary or supplemental health insurance. The secondary payer adjusts its payment based on what the primary health plan has already adjudicated or covered.