Final answer:
Coinsurance is the correct answer as it involves the insured party bearing a portion of the total costs, reducing moral hazard by providing an incentive to avoid excessive claims.
Step-by-step explanation:
The policy provision used to reduce moral hazard and attitudinal hazard is coinsurance. Coinsurance is when the policyholder is required to pay a certain percentage of the total costs, thus sharing the risk with the insurer.
Deductibles are the maximum out-of-pocket amounts that must be paid by the policyholder before the insurance company begins to pay. Copayments are flat fees that insured individuals must pay when receiving medical services. Moral hazard can be reduced by these mechanisms, as they involve the insured party bearing some cost, which incentivizes them to act in a way that minimizes the chances of a claim. Exclusion clauses and coordination of benefits are also part of insurance policies but are not directly related to sharing the cost burden with the insured.