CARC109ReferenceCurrentVerified Aug 15, 2026CARC 109
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 claim is not covered by this payer — it must be sent to the correct payer or contractor.
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
- Claim sent to the wrong payer
- Wrong payer ID or address used
- Coverage actually held by another plan
AR Guide knowledge
What AR should verify
- Verify which payer holds the coverage for the service date
- Confirm the payer ID and submission address used
AR Guide knowledge
Recommended action
- Send the claim to the correct payer
- If already billed elsewhere, confirm it was not paid twice
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.