Gov. Code, § 31631.5

(a) (1) Notwithstanding any other provision of this chapter, a board of supervisors or the governing body of a district may require that members pay 50 percent of the normal cost of benefits. However, that contribution shall be no more than 14 percent above the applicable normal rate of contribution of members established pursuant to this article for local general members, no more than 33 percent above the applicable normal rate of contribution of members established pursuant to Article 6.8 (commencing with Section 31639) for local police officers, local firefighters, county peace officers, and no more than 37 percent above the applicable normal rate of contribution of members established pursuant to Article 6.8 (commencing with Section 31639) for all local safety members other than police officers, firefighters, and county peace officers.

(2) Before implementing any change pursuant to this subdivision for any represented employees, the public employer shall complete the good faith bargaining process as required by law, including any impasse procedures requiring mediation and factfinding. This subdivision shall become operative on January 1, 2018. This subdivision shall not apply to any bargaining unit when the members of that unit are paying at least 50 percent of the normal cost of their pension benefit or are subject to an agreement reached pursuant to paragraph (1). Applicable normal rate of contribution of members means the statutorily authorized rate applicable to the member group as the statutes read on December 31, 2012.

(b) Nothing in this section shall modify a board of supervisors’ or the governing body of a district’s authority under law as it existed on December 31, 2012, including any restrictions on that authority, to change the amount of member contributions.