S.D. Codified Laws § 58-15-16
In the case of those policies issued prior to the operative date specified in § 58-15-42, the loan value referred to in § 58-15-15 is the reserve at the end of the current policy year on the policy and on any dividend additions thereto, computed according to a mortality table, interest rate, and method of valuation permitted by §§ 58-26-45 to 58-26-84, inclusive, less a sum not more than two and one-half percent of the amount insured by the policy and of any dividend additions thereto. The policy may provide that such loan may be deferred for not exceeding six months after application therefor, and shall contain a table showing in figures the loan values during at least the first twenty years of the policy or during the term of the policy, whichever is the shorter. However, in the case of a private placement policy, the policy may provide that the loan, or portions thereof, may be deferred until the separate account assets, or portion thereof, comprising such loan can be, by their respective terms, converted to cash.
SDCL 58-15-16