CO-131: Claim-Specific Negotiated Discount
Contractual adjustment — review against your contract terms. The patient is not liable for this amount.
What Does CO-131 Mean?
With CO (Contractual Obligation), the CARC 131 adjustment for claim-specific negotiated discount is a contractual reduction. The provider absorbs this amount per the payer contract or regulatory payment methodology. The patient is not responsible for the adjusted amount. Review the remittance to confirm the adjustment is consistent with your contract terms.
CARC 131 means the payer adjusted the payment based on claim-specific negotiated discount. The reimbursement was calculated using the payer's fee schedule, contracted rate, or regulatory payment methodology rather than the billed charge.
Common scenarios that trigger this adjustment include: a single-case agreement was negotiated between the provider and payer for a specific claim, and CARC 131 reflects the negotiated discount from the billed charges; The payer and provider agreed to a reduced rate for a specific claim or service, different from the standard contracted rate; An out-of-network provider negotiated a specific discount for a particular claim as part of the payment arrangement. The group code paired with CARC 131 determines who bears the financial responsibility — CO places it on the provider as a contractual obligation, OA indicates a coordination of benefits or other payer adjustment, PR shifts it to the patient.
Common Causes
| Cause | Frequency |
|---|---|
| Single-case agreement discount applied A single-case agreement was negotiated between the provider and payer for a specific claim, and CARC 131 reflects the negotiated discount from the billed charges | Most Common |
| Claim-specific rate reduction The payer and provider agreed to a reduced rate for a specific claim or service, different from the standard contracted rate | Common |
| Out-of-network negotiated discount An out-of-network provider negotiated a specific discount for a particular claim as part of the payment arrangement | Common |
| Workers' comp or auto insurance negotiated rate A negotiated rate was established for a workers' compensation or auto insurance claim that differs from the provider's standard charges | Occasional |
How to Resolve
- Review the adjustment against contract terms Compare the CO-131 adjustment with your payer contract to confirm the reduction is consistent with agreed terms or regulatory methodology.
- Verify the adjustment amount Confirm the dollar amount of the adjustment is calculated correctly based on the contracted rate and the service provided.
- Process the contractual adjustment If the adjustment is correct per contract terms, process it accordingly in your billing system. This amount cannot be transferred to the patient.
This is a voluntarily negotiated discount, not a denial. If the discount amount does not match the agreed terms, contact the payer to resolve it as a contract dispute.
Common RARC Pairings
The RARC code tells you exactly what triggered the CO-131:
| RARC | Description |
|---|---|
| N381 | This discount reflects a claim-specific negotiated rate per your agreement Verify the discount matches the terms of your single-case agreement or negotiated rate → |
How to Prevent CO-131
- Document all claim-specific negotiations in writing before services are rendered
- Track single-case agreements and their terms for accurate payment reconciliation
- Verify negotiated rates are loaded correctly in the payer's system before claim submission
- Negotiate realistic rates that account for the provider's cost of care
- Maintain organized records of all negotiated rate agreements by payer
Also Filed As
The same CARC 131 may appear with different Group Codes:
Related Denial Codes
Sources
- https://www.cms.gov/medicare/claims-appeals/organization-determinations
- https://www.aapc.com/resources/claim-adjustment-reason-code-carc
- https://www.mdclarity.com/denial-code/131
- Codes maintained by X12. Visit x12.org for official definitions.