S.D. Codified Laws § 3-12C-102
For the purposes of this chapter, the term, actuarial equivalent, is a benefit of equal value, computed on the basis of the interest rate, mortality, and baseline COLA assumptions adopted by the board for purposes of the actuarial valuation. If the board adopts a select and ultimate rate of interest, the interest rate is the ultimate rate. Mortality is based on a unisex rate that is fifty percent male and fifty percent female for employees and beneficiaries, based on the mortality rates for retired employees and beneficiaries, including, if the board adopts a generational mortality table, a generational projection of mortality improvement with the member's and beneficiary's ages as of the date of the calculation assumed to be in the calendar year in which the plan year containing the date of the calculation begins. If the board adopts distinct mortality tables for the different categories of retired members or beneficiaries, the mortality rates must be based on a weighted blend of the tables with the weighting based on the percentage of accrued benefits for each category of members as the actuarial valuation immediately preceding the date of adoption of the mortality tables. The system shall make the interest rate, mortality, and baseline COLA assumptions public.
SDCL 3-12C-102