CARC 2 Active

CO-2: Coinsurance Amount

TL;DR

Contractual adjustment — review against your contract terms. The patient is not liable for this amount.

Action
Review & Decide
Who Pays
Provider
Appeal
No
Patient Impact
None
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-2 Mean?

With CO (Contractual Obligation), the CARC 2 adjustment for coinsurance amount 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 2 appears on a remittance when the payer adjusts payment for the coinsurance amount. This is a standard plan-defined cost-sharing amount that the patient is obligated to pay per their insurance benefits. The code confirms the payer processed the claim correctly and applied the plan's benefit structure as designed.

Common scenarios that trigger this adjustment include: patient's plan requires a percentage cost-sharing for covered services after deductible is met; Higher coinsurance percentage applied for services from out-of-network providers; Specific service categories carry different coinsurance rates per the plan design. The group code paired with CARC 2 determines who bears the financial responsibility — PR shifts it to the patient, OA indicates a coordination of benefits or other payer adjustment, CO places it on the provider as a contractual obligation.

How to Resolve

  1. Review the adjustment against contract terms Compare the CO-2 adjustment with your payer contract to confirm the reduction is consistent with agreed terms or regulatory methodology.
  2. Verify the adjustment amount Confirm the dollar amount of the adjustment is calculated correctly based on the contracted rate and the service provided.
  3. Appeal if the adjustment is incorrect If the adjustment does not align with contract terms, file an appeal with contract documentation and supporting evidence.
  4. 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.
Do Not Appeal This Code

Coinsurance Amount represents an amount the patient owes per their plan benefits — usually a deductible, coinsurance, or copay calculated against plan terms. Since the calculation comes from the benefits rather than a coverage denial, appeals don't apply. Verify the calculation against the patient's plan and collect the patient portion.

How to Prevent CO-2

Also Filed As

The same CARC 2 may appear with different Group Codes:

Related Denial Codes

Sources

  1. https://x12.org/codes/claim-adjustment-reason-codes
  2. https://www.mdclarity.com/denial-code/2
  3. https://revenuecyclemgmt.com/claim-adjustment-reason-codes/
  4. https://www.rivethealth.com/blog/carcs-rarcs-claim-adjustment-remittance-advice-codes
  5. Codes maintained by X12. Visit x12.org for official definitions.