Denial Resolution Center
Medical Billing Denial Codes, Root Causes, and Resolution Paths
Start with the group code, CARC, every RARC, claim status, and payer notice. Then route the account to correction, inquiry, reopening, appeal, or contractual review.
Rejected
The claim failed format or front-end edits before adjudication.
Correct and resubmit
Denied
The payer adjudicated but did not allow all or part of the claim.
Read the full remittance and determination
Reduced
The payer allowed the service but adjusted charge, units, code, or payment.
Contractual, coding, or payment review
Pending
The payer needs time or additional information before a final decision.
Respond and monitor the deadline
22 denial guides
CARC 16: Missing or Invalid Claim Information
CARC 16 is a broad signal that required claim information is missing, incomplete, invalid, or inconsistent. The associated RARC and claim-level context identify the actual field or relationship to fix.
CARC 18: Duplicate Claim or Service
A duplicate adjustment means the payer believes the same service was already submitted or adjudicated. The correct action depends on whether the prior claim is paid, pending, denied, voided, or materially different.
CARC 22: Coordination of Benefits and Payer Order
This denial family commonly indicates that another payer may have primary responsibility or that primary-payer adjudication data is missing or inconsistent.
CARC 29: Timely Filing Denial
A timely-filing denial means the payer determined the claim arrived after its filing period. For Original Medicare, the general limit is one calendar year and this denial is generally not an appealable initial determination.
CARC 97: Service Included in Another Payment
This adjustment family indicates that payment for the service is considered included in another service or allowance. The underlying rule may be NCCI, global surgery, facility packaging, or another payment policy.
CARC 109: Claim Sent to the Wrong Payer or Contractor
The receiving payer or contractor is not responsible for the claim under the member, plan, jurisdiction, contract, or service facts.
CARC 197: Prior Authorization Missing
This denial family indicates that required authorization, precertification, or notification was not obtained or did not match the claim facts.
Missing Order or Standard Written Order
The payer could not verify a required order, its elements, its timing, or the ordering provider's eligibility for the billed item or service.
Insufficient Medical Necessity Documentation
The submitted record did not demonstrate that the service, level, quantity, frequency, or setting met applicable coverage and payment requirements.
Missing, Invalid, or Unsupported Modifier
The modifier may be absent, invalid for the code, inconsistent with other claim facts, or unsupported by the record.
Diagnosis Does Not Support the Billed Service
The claim diagnosis may be invalid, incorrectly sequenced, disconnected from the service line, or insufficient to show coverage under the applicable policy.
Frequency or Benefit Limit Exceeded
The quantity or timing exceeds a policy, benefit, utilization, or replacement limit, or the payer history contains an earlier service that conflicts with the claim.
NCCI MUE or Units-of-Service Denial
The billed units exceeded a Medicare MUE or another payer's utilization edit, or the unit definition was calculated incorrectly.
Same or Similar Equipment Denial
Claim history suggests the beneficiary already received equipment that may serve the same medical purpose or has not met replacement requirements.
Proof of Delivery Missing or Incomplete
The record does not establish that the billed item and quantity were delivered to the correct beneficiary through an allowed method on the reported date.
Prior Authorization Missing or Does Not Match
The payer expected authorization, or the approval does not match the billed provider, service, setting, units, or dates.
Noncovered Item or Service
The denial may reflect a statutory exclusion, benefit-plan exclusion, lack of a Medicare benefit category, or failure to meet a coverage policy. These are different legal and operational reasons.
Provider or Supplier Not Eligible to Bill
The billing, rendering, ordering, referring, attending, or supplier enrollment facts do not support payment for the claim and service date.
Continued Use Documentation Missing
The payer could not verify that the beneficiary continues to use the equipment or service under the applicable policy timing and evidence rules.
Continued Medical Need Documentation Missing
The record does not support that the item or service remains reasonable and necessary during the billed period.
DME Repair Documentation Incomplete
The repair claim does not show the equipment, ownership, failure, part, labor, medical need, warranty status, or reason repair is reasonable.
Replacement Justification Missing
The record does not establish why replacement is payable instead of continued use or repair of the existing item.