Cal. Education Code § 22140

(a) “Improvement factor,” with respect to the Defined Benefit Program, means an increase of 2 percent in monthly allowances. The improvement factor shall be added to a monthly allowance each year on September 1, commencing on September 1 following the first anniversary of the effective date of retirement, or the date on which the monthly allowance commenced to accrue to any beneficiary, or other periods specifically stated in this part. (b) The improvement factor may not be compounded nor shall it be applicable to annuities payable from the accumulated annuity deposit contributions or the accumulated tax-sheltered annuity contributions. (c) Beginning July 1, 2014, the improvement factor shall vest for an active member in any calendar year in which active members paid increased member contributions pursuant to Section 22901.7. (d) If, for any reason, the increased employee contribution referenced in subdivision (c), and as required by subdivisions (a) and (b) of Section 22901.7, ceases to be legally required to be made pursuant to the act that added this subdivision, then the Legislature reserves the right to adjust the amount of the improvement factor up or down as the economic conditions dictate for all members who retire on or after January 1, 2014. No adjustments of the improvement factor shall reduce the monthly retirement allowance or benefit below that which would be payable to the recipient under this part had this section not been enacted. (e) For members who retired before the calendar year in which Section 22901.7 was added the Legislature reserves the right to adjust the amount of the improvement factor up or down as economic conditions dictate. Any adjustment of the improvement factor may not reduce the monthly retirement allowance or annuity below that which would be payable to the recipient under this part had this section not been enacted.