Nothing in this part shall be construed to prohibit the withholding of insurance premiums for retirees under a plan approved by the state insurance committee, or for retired teachers or other retired local government employees for payment of insurance premiums under any Tennessee local government group insurance plan provided to the retirees. The director of the Tennessee consolidated retirement system may periodically establish a schedule of insurance premium support levels that local education agencies (LEAs) may assign to the retired teachers. If a schedule is established, an LEA must conform to the schedule in order for the retirement system to make or continue making premium payment deductions from the retirement benefits of that LEA's retired teachers.