DenialDenial Code Reference
Search CARC (Claim Adjustment Reason Codes) and RARC (Remittance Advice Remark Codes) by code number or keyword. Each entry includes the standard description and a plain-English action step. Filter by code type or group code (CO, PR, OA, PI).
Common CARC codes
173 codes total — 100 CARC · 73 RARC
Group Code Quick Reference
CO — Contractual Obligation
Amounts the provider agreed to write off per their contract with the payer. These are not patient responsibility. Examples: CO-45 (contracted rate), CO-97 (bundled service).
PR — Patient Responsibility
Amounts the patient is responsible for paying. Can be billed to the patient or their secondary insurance. Examples: PR-1 (deductible), PR-2 (coinsurance), PR-3 (copay).
OA — Other Adjustment
Adjustments that do not fall into CO or PR. May include prior payments, capitation offsets, or informational adjustments. Patient cannot be billed.
PI — Payer Initiated
Reductions initiated by the payer that are not the provider contractual obligation and not billed to the patient. Informational in most cases.
CARC vs. RARC
CARC codes (numbered, e.g. 97, 50, 4) explain why a payment was adjusted — they always appear with a group code on the remittance. RARC codes (MA, N, M prefix) provide supplemental remarks — additional context, alerts, or instructions that accompany a CARC. A single claim line can have multiple RARCs.
CARC and RARC codes are published by the Washington Publishing Company (WPC) and maintained by CMS. Codes are updated periodically — verify current descriptions against the most recent WPC release for high-stakes appeals.