Cal. Gov. Code § 21200
When any person is reinstated from retirement under this article, his or her retirement allowance shall be canceled immediately, and he or she shall become a member of this system as of the date of reinstatement. His or her individual account shall be credited with an amount that is the actuarial equivalent of his or her annuity at the date of reinstatement, not to exceed the amount of his or her accumulated contributions as it was at the date of retirement. His or her future rate of contributions and his or her retirement allowance upon subsequent retirement shall be determined in accordance with Chapter 8 (commencing with Section 20670) and Chapter 13 (commencing with Section 21250), respectively.
The actuarial equivalent under this section shall be adjusted by the board every 10 years, or more frequently, to agree with the interest rate and mortality tables in effect at the commencement of each such 10-year or succeeding interval.
Ca. Gov. Code § 21200