S.D. Codified Laws § 58-15-60
In an annuity or pure endowment contract, other than a reversionary, survivorship, or group annuity, there shall be a provision that if the age or sex of the person upon whose life the contract is made, or if any of them has been misstated, the amount payable or benefits accruing under the contract shall be such as the stipulated payments to the insurer would have purchased according to the correct age or sex and that if the insurer shall make or has made any overpayment on account of any such misstatement, the amount thereof with interest at the rate to be specified in the contract but not exceeding six percent per annum, may be charged against the current or next succeeding payments to be made by the insurer under the contract.
SDCL 58-15-60