Cal. Education Code § 24409

The minimum unmodified allowance, exclusive of annuities from accumulated annuity deposit and tax-sheltered contributions, of (a) a person who retired on or before December 31, 1981, (b) the option beneficiary of a person who retired on or before December 31, 1981, or (c) a person receiving a monthly allowance in lieu of the death benefit payable on account of the death of a member whose death occurred prior to July 1, 1972, shall be an amount equal to at least eighteen dollars ($18) per month multiplied by the years of credited service. This guaranteed amount is increased as of September 1, 1981, and is applicable to allowances paid on and after September 1, 1981. If the retirement was effective at less than age 60 years, this allowance shall be reduced by one-quarter of 1 percent for each full month or fraction of a month that would have elapsed until the retired member reached age 55 years, and the allowance shall be reduced by one-half of 1 percent for each full month or fraction of a month between age 55 and age 60 years. If the retired member elected to have his or her allowance modified under Option 2 or 3, the increase in the retired member’s allowance shall be modified under the option selected.