The way benefits carriers work together when a person has dual coverage is called coordination of benefits or COB. Dual coverage does not mean double benefits. For example, if both of your plans cover two cleanings per year, having dual coverage won't provide coverage for four cleanings.
Understanding Medicaid Coordination of Benefits
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eCFR :: 29 CFR Part 2590 -- Rules and Regulations for Group Health Plans
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eCFR :: 29 CFR Part 2590 -- Rules and Regulations for Group Health Plans
Understanding dual coverage
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