CARC — Claim Adjustment Reason Codes
CARCs appear in the 835 remittance advice CAS segment and tell you why the payer paid less than the billed amount — bundling, medical necessity, prior-auth gaps, timely-filing, patient responsibility, and contractual adjustments. 306 codes seeded, ordered by US search demand. Every leaf page cites the official X12 description and pairs the RARC partners typically observed on the 835. Source: X12 External Code Lists.
Reviewed by QuickIntell Editorial Team · Last reviewed
UpdatedFilter by root-cause category
All CARCs306Bundling / NCCI8Coding / modifier18Medical necessity8Prior authorization15Coverage / eligibility29Timely filing2Patient responsibility20Duplicate2Contractual21Other183
Showing 2 of 306 CARCs in Duplicate.
| Rank | Code | Description (X12) | Category | US search / mo |
|---|---|---|---|---|
| #10 | CARC B13 | Previously paid. Payment for this claim/service may have been provided in a previous payment. | Duplicate | 390 |
| #17 | CARC 18 | Exact duplicate claim/service | Duplicate | 240 |
Paired with a RARC?
Most CARCs arrive on the 835 alongside one or more Remittance Advice Remark Codes that narrow the reason. See the RARC remark-code reference for the paired explanations.