CA Gov't Code Section 66540.61

As an alternative method of providing a retirement system, the board may contract with the Board of Administration of the Public Employees’ Retirement System and enter all or any portion of its employees under that system pursuant to law and under the terms and conditions of that contract, or may contract with the Board of Administration of the Public Employees’ Retirement System for reciprocal benefits between the Public Employees’ System, or a city, or city and county, or any other public agency contracting with the Public Employees’ Retirement System and the authority’s retirement system as authorized by Section 20042, and may perform all acts necessary or convenient to provide for those reciprocal benefits.