The county shall pay all or that portion of monthly premiums for health insurance for all eligible permanent employees and eligible dependents as set forth in the most recently adopted memorandum of understanding with the applicable bargaining units.

Notwithstanding any other provisions of this code, permanent part-time employees working a minimum of 50 percent of a full-time equivalent position (FTE) shall be eligible to participate in health plans provided by the county; provided, that the county shall fund only a portion of such employee’s participation cost prorated based upon the percentage of FTE employment for the employee’s position. Where approved personnel actions do not establish an employee’s work time, eligibility for county contribution shall be based on the percentage of full-time equivalent work as performed by the employee during the preceding six-month period. Costs of participation shall be based upon the premium cost paid by the county for full-time employees.