(

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 of Title of the United States Code, a tax-deferred retirement plan that meets the requirements of

Section 40l(

k) of Title 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 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 of the United States Code, provided all of the following conditions exist:

(1) The defined benefit plan provided under this

chapter has been designated as the employer’s primary plan for the person and the supplemental defined benefit plan is adopted by the governing body of the employer.

(2) The supplemental defined benefit plan has received a ruling from the Internal Revenue Service stating that the plan qualifies under

Section 401(

a) of Title of the United States Code, and has furnished proof thereof to the employer.

(3) The person’s participation in the supplemental defined benefit plan does not, in any way, interfere with the person’s rights to membership in the defined benefit plan, or any benefit provided, under this chapter. (

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 for all or any portion of his or her membership in the county retirement system.