Existing law, the California Public Employees' Pension Reform Act of 2013 (PEPRA) , on and after January 1, 2013, requires a public retirement system, as defined, to modify its plan or plans to comply with PEPRA, as specified. Among other things, PEPRA prohibits a public employer from offering a defined benefit pension plan exceeding specified retirement formulas, requires new members of public retirement systems to contribute at least a specified amount of the normal cost, as defined, for their defined benefit plans, and prohibits an enhancement of a public employee's retirement formula or benefit adopted after January 1, 2013, from applying to service performed prior to the operative date of the enhancement. PEPRA prohibits a public employer from offering a supplemental defined benefit plan if the public employer did not do so before January 1, 2013, or, if it did, from offering that plan to an additional employee group after that date. This bill would authorize a public employer, as defined, to bargain over contributions for supplemental retirement benefits administered by, or on behalf of, an exclusive bargaining representative of one or more of the public employer's bargaining units, subject to the limitations specified above.