(a) The System shall conduct a divided medicare coverage referendum, open to employees continuously employed by the same employer since March 31, 1986. The referendum shall be conducted in accordance with the applicable provisions of federal law and Article 21 of this Code.
     (b) As used in this Section and in compliance with federal law, “referendum” means the process whereby employees are granted the opportunity to make an irrevocable individual election to participate in the medicare program on a prospective basis.
     (c) Employers shall pay the necessary employer contributions and make the necessary deductions from salary for employees who elect to participate in the federal medicare program under this Section, as required by the System, Article 21 of this Code, and federal law.