California Code, Government Code - GOV § 31485.21

(a) A member who has not attained normal retirement age shall have a bona fide separation from service to the extent required by Section 401(a) of Title 26 of the United States Code before working for the county or a district.  The board shall establish, by regulation, the criteria under which a bona fide separation is satisfied.

(b) Notwithstanding any other provision of this chapter, to the extent required or permitted by Section 401(a) of Title 26 of the United States Code, no amount shall be paid to any member before the date the member has attained normal retirement age or has had a bona fide separation from service, whichever is earlier.

(c) The board may establish, by regulation, normal retirement age consistent with federal law and eligibility requirements under state law.

(d) To the extent that the California Public Employees' Pension Reform Act of 2013 (Article 4 (commencing with Section 7522) of Chapter 21 of Division 7 of Title 1) would provide for greater restrictions with regard to separation from service, the provisions of that act shall prevail.