What Is Coordination of Benefits?
Coordination of Benefits (COB) is the process that determines how two health insurance plans split payment when an insured person is covered by more than one plan.
Primary vs Secondary Plan
- Primary plan: Processes the claim first and pays according to its normal terms
- Secondary plan: Pays some or all of what the primary plan didn't cover
The combined payment from both plans cannot exceed 100% of the actual cost of care.
How Primary Plan Is Determined
- Employee's own employer plan is primary for the employee
- Birthday rule for children: Parent with birthday earliest in the calendar year is primary
- Medicare rules depend on employer size and type of coverage
💡 With effective COB, your out-of-pocket costs can be dramatically reduced or even eliminated. The secondary plan pays what the primary left behind.
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