Instantly find explanations, causes, and resolution steps for every Claim Adjustment Reason Code (CARC) and Remark Code.
Claim Adjustment Reason Codes (CARC) explain why a payment differs from what was billed. Every 835 ERA and EOB uses these standardized codes.
Search any code or keyword above. Each page includes the full description, common causes, resolution steps, and appeal guidance.
Each denial code page also links to a dedicated Remark Code page — optimized for providers searching for ERA remark code context.
Most denials are reversible. Our guides walk you through the correct steps to correct, resubmit, or formally appeal each denial type.
| Code | Description | View |
|---|---|---|
| N267 | Missing/incomplete/invalid ordering provider secondary identifier. | Details → |
| N267 | Missing/incomplete/invalid ordering provider secondary identifier. | Details → |
| N268 | Missing/incomplete/invalid ordering provider contact information. | Details → |
| N268 | Missing/incomplete/invalid ordering provider contact information. | Details → |
| N269 | Missing/incomplete/invalid other provider name. | Details → |
| N269 | Missing/incomplete/invalid other provider name. | Details → |
| N27 | Missing/incomplete/invalid treatment number. | Details → |
| N27 | Missing/incomplete/invalid treatment number. | Details → |
| N270 | Missing/incomplete/invalid other provider primary identifier. | Details → |
| N270 | Missing/incomplete/invalid other provider primary identifier. | Details → |
| N271 | Missing/incomplete/invalid other provider secondary identifier. | Details → |
| N271 | Missing/incomplete/invalid other provider secondary identifier. | Details → |
| N272 | Missing/incomplete/invalid other payer attending provider identifier. | Details → |
| N272 | Missing/incomplete/invalid other payer attending provider identifier. | Details → |
| N273 | Missing/incomplete/invalid other payer operating provider identifier. | Details → |
| N273 | Missing/incomplete/invalid other payer operating provider identifier. | Details → |
| N274 | Missing/incomplete/invalid other payer other provider identifier. | Details → |
| N274 | Missing/incomplete/invalid other payer other provider identifier. | Details → |
| N275 | Missing/incomplete/invalid other payer purchased service provider identifier. | Details → |
| N275 | Missing/incomplete/invalid other payer purchased service provider identifier. | Details → |
| N276 | Missing/incomplete/invalid other payer referring provider identifier. | Details → |
| N276 | Item(s) billed did not have a valid ordering physician National Provider Identifier (… | Details → |
| N276 | Missing/incomplete/invalid other payer referring provider identifier. | Details → |
| N277 | Missing/incomplete/invalid other payer rendering provider identifier. | Details → |
| N277 | Missing/incomplete/invalid other payer rendering provider identifier. | Details → |
| N278 | Missing/incomplete/invalid other payer service facility provider identifier. | Details → |
| N278 | Missing/incomplete/invalid other payer service facility provider identifier. | Details → |
| N279 | Missing/incomplete/invalid pay-to provider name. | Details → |
| N279 | Missing/incomplete/invalid pay-to provider name. | Details → |
| N28 | Consent form requirements not fulfilled. | Details → |
| N28 | Consent form requirements not fulfilled. | Details → |
| N280 | Missing/incomplete/invalid pay-to provider primary identifier. | Details → |
| N280 | Missing/incomplete/invalid pay-to provider primary identifier. | Details → |
| N281 | Missing/incomplete/invalid pay-to provider address. | Details → |
| N281 | Missing/incomplete/invalid pay-to provider address. | Details → |
| N282 | Missing/incomplete/invalid pay-to provider secondary identifier. | Details → |
| N282 | Missing/incomplete/invalid pay-to provider secondary identifier. | Details → |
| N283 | Missing/incomplete/invalid purchased service provider identifier. | Details → |
| N283 | Missing/incomplete/invalid purchased service provider identifier. | Details → |
| N284 | Missing/incomplete/invalid referring provider taxonomy. | Details → |
| N284 | Missing/incomplete/invalid referring provider taxonomy. | Details → |
| N285 | Missing/incomplete/invalid referring provider name. | Details → |
| N285 | Missing/incomplete/invalid referring provider name. | Details → |
| N286 | Missing/incomplete/invalid referring provider primary identifier. | Details → |
| N286 | The referring provider identifier is missing, incomplete or invalid | Details → |
| N286 | Missing/incomplete/invalid referring provider primary identifier. | Details → |
| N287 | Missing/incomplete/invalid referring provider secondary identifier. | Details → |
| N287 | Missing/incomplete/invalid referring provider secondary identifier. | Details → |
| N288 | Missing/incomplete/invalid rendering provider taxonomy. | Details → |
| N288 | Missing/incomplete/invalid rendering provider taxonomy. | Details → |
| N289 | Missing/incomplete/invalid rendering provider name. | Details → |
| N289 | Missing/incomplete/invalid rendering provider name. | Details → |
| N29 | Missing documentation/orders/notes/summary/report/chart. | Details → |
| N29 | Missing documentation/orders/notes/summary/report/chart. | Details → |
| N290 | Missing/incomplete/invalid rendering provider primary identifier. | Details → |
| N290 | Missing/incomplete/invalid rendering provider primary identifier. | Details → |
| N291 | Missing/incomplete/invalid rendering provider secondary identifier. | Details → |
| N291 | Missing/incomplete/invalid rendering provider secondary identifier. | Details → |
| N292 | Missing/incomplete/invalid service facility name. | Details → |
| N292 | Missing/incomplete/invalid service facility name. | Details → |
Medical claim denial codes — formally known as Claim Adjustment Reason Codes (CARC) — are standardized identifiers maintained by the X12 standards body and used across all Medicare, Medicaid, and commercial payer 835 electronic remittance transactions. When a claim is paid at a different amount than billed, at least one CARC code must accompany the remittance advice to indicate the specific reason for the adjustment.
The most frequently encountered codes include CO-16 (missing or invalid claim information), CO-45 (charges exceeding fee schedule), PR-1 (patient deductible), CO-29 (timely filing deadline exceeded), and CO-4 (procedure code inconsistent with modifier). Each represents a distinct, actionable reason that has a defined resolution pathway.