Final answer:
Supplemental insurance plans usually cover deductibles, copayments, and coinsurance. These are payments shared between the insurance company and the policyholder, and they serve to reduce moral hazard.
Step-by-step explanation:
Deductibles, copayments, and coinsurance are typically covered by a supplemental insurance plan. These are out-of-pocket costs that the insured must pay as a part of their health insurance policy. A deductible is the amount paid out-of-pocket by the policyholder before the insurance coverage starts to pay. A copayment is a fixed fee the policyholder pays for a specific service or prescription, and coinsurance is the percentage of costs that the policyholder pays after the deductible has been met. Together, they are designed to share the cost between the insurer and the insured, thus reducing moral hazard by giving the insured an incentive to avoid unnecessary medical costs.