California Code, Government Code - GOV § 31540

(a) The obligations of the retirement system to its members continue throughout their respective memberships, and the obligations of the retirement system to, and in respect to, retired members continue throughout the lives of the retired members, and thereafter until all obligations to the members' beneficiaries under optional settlements have been discharged. The obligations of the county or district to the retirement system with respect to members employed by them, respectively, continue throughout the memberships of the members, and the obligations of the county or district to the retirement system with respect to retired members formerly employed by them, respectively, continue until all of the obligations of the retirement system to those retired members have been discharged. The obligations of any member to the retirement system continue throughout his or her membership, and thereafter until all of the obligations of the retirement system to that member have been discharged.

(b) For the purposes of payments into or out of the retirement fund for adjustment of errors or omissions, the period of limitation of actions shall be three years, and shall be applied as follows:

(c) Notwithstanding subdivision (b), in cases in which payment is erroneous because of the death of the retired member or beneficiary or because of the remarriage of the beneficiary, the period of limitation shall be 10 years and that period shall commence with the discovery of the erroneous payment.

(d) Notwithstanding subdivision (b), if any payment has been made as a result of fraudulent reports for compensation made, or caused to be made, by a member for his or her own benefit, the period of limitation shall be 10 years and that period shall commence either from the date of payment or upon discovery of the fraudulent reporting, whichever date is later.

(e) The board shall determine the applicability of the period of limitation in any case, and its determination with respect to the running of any period of limitation shall be conclusive and binding for purposes of correcting the error or omission.

(f) This section shall apply only to a county of the first class as described in Section 28020.