S.D. Codified Laws § 58-15-43.4
Except as otherwise provided in § 58-15-43.7, the recalculated future adjusted premiums for any such policy shall be such uniform percentage of the respective future premiums specified in the policy for each policy year, excluding amounts payable as extra premiums to cover impairments and special hazards, and also excluding any uniform annual contract charge or policy fee specified in the policy in a statement of the method to be used in calculating the cash surrender values and paid-up nonforfeiture benefits, that the present value, at the time of change to the newly defined benefits or premiums, of all the future adjusted premiums is equal to the excess of (A) the sum of the then present value of the then future guaranteed benefits provided for by the policy and the additional expense allowance, if any, over (B) the then cash surrender value, if any, or present value of any paid-up nonforfeiture benefit under the policy.
SDCL 58-15-43.4