CARC23ReferenceCurrentVerified Aug 15, 2026CARC 23
AR Guide Workflow
Coordination of Benefits
Another plan may be primary, the primary's payment was not applied correctly, or the claim belongs with a different payer under COB rules.
AR Guide explanation
What it means
The adjustment reflects how a prior payer's payment and adjustments affect this claim. Used with group code OA.
AR Guide knowledge
Common denial category
Coordination of Benefits — Another plan may be primary, the primary's payment was not applied correctly, or the claim belongs with a different payer under COB rules.
AR Guide knowledge
Common causes
- Secondary claim processed after primary payment
- Prior payer's payment applied to patient responsibility
AR Guide knowledge
What AR should verify
- Compare the primary payer's EOB/ERA with this adjustment
- Confirm the amounts reconcile
AR Guide knowledge
Recommended action
- Bill the patient only for the remaining patient responsibility per the plan
- If the secondary calculation looks wrong, request a recalculation with the primary EOB
About this guidance: Note
AR Guide knowledge is general reference content written by our team — it is not payer-specific policy and never replaces the payer’s documentation or your contract. Always confirm specifics with the payer.