S.D. Codified Laws § 58-26-56
Except as provided in §§ 58-26-64 to 58-26-74, inclusive, and § 58-26-84, the minimum standard for the valuation of policies and contracts issued prior to July 1, 1995, shall be that provided by the laws in effect immediately prior to July 1, 1995. Except as otherwise provided in §§ 58-26-64 to 58-26-74, inclusive, and § 58-26-84, the minimum standard for the valuation of all policies and contracts issued on or after July 1, 1995, shall be the commissioners' reserve valuation methods defined in §§ 58-26-75, 58-26-76, 58-26-81, 58-26-82, and 58-26-84, three and one-half percent interest, or in the case of life insurance policies and contracts, other than annuity and pure endowment contracts, issued on or after July 1, 1973, four percent interest for such policies issued prior to July 1, 1978, five and one-half percent interest for single premium life insurance policies and four and one-half percent interest for all other policies issued on and after July 1, 1978, and the tables provided for in §§ 58-26-57 to 58-26-63, inclusive.
SDCL 58-26-56