(1) Notwithstanding any other provision of this subchapter, a plan beneficiary who is also eligible for Medicare is subject to the limitations and benefits provided for in this rule.

(2) Reimbursement for outpatient drugs provided to plan beneficiaries who are also eligible for Medicare are limited to medically necessary barbiturates and benzodiazepines prescribed for the treatment of mental illness.

(3) Reimbursement will not be made for drugs for which payment as prescribed and dispensed or administered to an individual is available for that individual under Medicare Part A, Part B, or Part D even though the individual is eligible for coverage under Medicare but has declined to enroll in Part A, Part B, or Part D.

(4) Additional assistance will be provided plan beneficiaries who are also eligible for Medicare as follows:

(a) beneficiaries eligible for full subsidy extra help through the Social Security Administration will receive no additional assistance through the plan;

(b) beneficiaries eligible for partial subsidy extra help through the Social Security Administration will receive plan assistance with annual deductibles and coinsurance, for drugs prescribed for the treatment of mental illness up to a combined maximum of $425.00 per month; or

(c) beneficiaries not eligible for subsidy extra help through the Social Security Administration will receive plan assistance with annual deductibles, coinsurance, and cost-sharing within the coverage gap, for drugs prescribed for the treatment of mental illness up to a combined maximum of $425.00 per month.

(5) Reimbursement will be made only for services for which third party payment is not available.