A Medicare supplement insurance plan does NOT pay the cost-sharing of which type of plan?

Medicare supplement insurance plans, also known as Medigap plans, are designed to cover certain costs that Original Medicare does not pay, such as copayments, coinsurance, and deductibles. However, these plans do not coordinate with Medicare Advantage (MA) plans.

Medicare Advantage plans, which are offered by private insurers, provide all of the benefits of Medicare Parts A and B and often include additional benefits. When an individual is enrolled in a Medicare Advantage plan, they are not using Original Medicare for their coverage, so a Medigap policy would not apply. Medigap plans specifically work in conjunction with Original Medicare and do not cover out-of-pocket costs for services received under a Medicare Advantage plan.

On the other hand, HMO, PPO, and Medicaid plans have different structures but can still involve cost-sharing that Medigap policies could potentially cover, assuming the individual remains within the scope of Original Medicare for their benefits. This distinction helps clarify why Medicare supplement plans do not address co-pays or costs in the context of Medicare Advantage plans.