Category summary: COB denials are won by proving payer order and attaching the correct primary-payer adjudication when required.
Top codes in this category
How to work these denials
- Verify payer order using eligibility, member COB updates, Medicare records, and plan coordination rules.
- Attach the primary payer EOB/ERA or explain why BCBS is primary.
- Submit secondary claim data with correct CAS segments, paid amount, deductible, coinsurance, and adjustment information.
- Ask the member to complete COB updates if the payer requires member response.
- Appeal only after payer order and primary adjudication proof are clean.
Evidence checklist
- Primary payer EOB/ERA
- COB questionnaire status
- Eligibility responses
- Medicare crossover record
- Accident/workers compensation notes
- Secondary claim extract
Guides in this cluster
- BlueCard Denial Workflow: Host Plan, Home Plan and Local BCBS Claims
- BCBS Coordination of Benefits Denials: CO-22, OA-23, N479 and N480
- BCBS Missing EOB for COB: N479 and N480 Workflow
- BCBS Medicare Crossover Duplicate Claim Denials: N522 and CO-18
- BlueCard Host Plan vs Home Plan: Claims and Denial Follow-Up