CARC 2: Coinsurance amount
This is the patient's coinsurance share, a percentage of the allowed amount, which the patient owes.
Group code context
Usually sent with group code PR (patient responsibility): the amount is owed by the patient, not written off.
Common causes
- Plan pays a percentage (for example 80%) and the patient pays the rest
Step-by-step fix
- Check that the coinsurance percentage matches the patient's benefits
- Post as patient responsibility
- Bill the secondary payer if the patient has one, otherwise the patient
Appeal guidance
Appeal only if the payer used the wrong coinsurance rate, for example out-of-network instead of in-network.
When not to appeal
Do not appeal correct coinsurance. If there is secondary coverage, bill it instead.
Prevention checklist
- Verify coinsurance and secondary coverage before the visit
- Estimate patient cost for larger procedures
Related codes
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Source and review
Official source ↗Last checked: 2026-10-05
Reviewed by: PracticeVendors editorial team
Educational reference. Confirm payer instructions and applicable contracts before taking action.