California Code, Government Code - GOV § 31482.5

(a) Notwithstanding any provisions to the contrary in Section 20894, this section shall apply to all participants in retirement systems governed by this chapter.

(b) A person shall not receive credit for the same service in two retirement systems supported wholly or in part by public funds under any circumstance.

(c) Nothing in this section shall preclude concurrent participation and credit for service in a public retirement system and in a deferred compensation plan that meets the requirements of Section 457 of Title 26 of the United States Code, a tax-deferred retirement plan that meets the requirements of Section 40l(k) of Title 26 of the United States Code, or a defined contribution plan and trust that meets the requirements of Section 401(a), 403(b), or 415(m) of Title 26 of the United States Code.

(d) Nothing in this section shall preclude concurrent participation and credit for service in the defined benefit plan provided under this chapter and in a supplemental defined benefit plan maintained by the employer that meets the requirements of Section 401(a) of Title 26 of the United States Code, provided all of the following conditions exist:

(e) If any provision of this section conflicts with the California Public Employees' Pension Reform Act of 2013, that provision shall not apply to a member who is subject to the California Public Employees' Pension Reform Act of 2013 for all or any portion of his or her membership in the county retirement system.