California Code, Government Code - GOV § 31648.3

A member who is a full-time employee and returns within 12 months of the date of layoff to full-time service following a period of layoff commencing on or after January 1, 1981, but not to exceed 12 months, may receive service credit for the period of the absence, but not to exceed one year, upon the payment of the contributions that the member would have paid during that period, together with the interest that the contributions would have earned had they been on deposit, if the member was not absent. The contributions may be paid in lump sum or may be paid on a monthly basis for a period of not more than the length of the period for which service credit is claimed. The service credit provided by this section shall be provided only to persons who have returned to employment under the procedures of the employer for returning laid-off employees to work and shall not exceed one year of service credit for each layoff period. The decision of the member to redeposit withdrawn contributions shall be made within five years from the date the member is rehired or the effective date of the adoption by the county board of supervisors of this section. Upon completion of the redeposit with interest, the entry age of the member shall be adjusted to the original age of entry and membership is reestablished to that date.

This section shall not be operative in any county until such time as the board of supervisors shall, by resolution adopted by a majority vote, make this section applicable in the county.