Section 25. Notwithstanding any general or special law or regulation to the contrary, the appropriate public authority of a political subdivision which has undertaken to provide health insurance coverage to its subscribers under this chapter or transfer its subscribers to the commission under this chapter may provide health reimbursement arrangements to reimburse subscribers for qualified medical expenses which may include, but shall not be limited to, out-of-pocket costs such as inpatient and outpatient copayments, calendar year deductibles, office visit copayments and prescription drug copayments.