(1) The legislature shall establish as part of both the state employees' and the school and educational service district employees' insurance benefit allocation the portion of the allocation to be used to provide a subsidy to reduce the medical and prescription drug insurance premium charged to retired or disabled school district and educational service district employees, or retired state employees, who are eligible for parts A and B of medicare.
(2) The amount of any premium reduction shall be established by the public employees' benefits board. The amount established shall not result in a premium reduction of more than fifty percent, except as provided in subsection (3) of this section. The public employees' benefits board may also determine the amount of any subsidy to be available to spouses and dependents.
(3) The amount of the premium reduction in subsection (2) of this section may exceed fifty percent, if the director, in consultation with the office of financial management, determines that it is necessary in order to meet eligibility requirements to participate in the federal employer incentive program as provided in RCW
41.05.068.