S.D. Codified Laws § 21-52-14
Any redemptioner may redeem from the purchaser at any sale described in § 21-52-1, by paying to the sheriff or other person appointed by a court to make the sale, the amount of the purchase price, plus any sums paid by the purchaser to protect his interest in such property for taxes, insurance, installments of principal or interest upon a superior lien, with interest at the legal rate as specified in § 54-3-5.1 from date of sale upon the purchase price of the property, and from the date of the payment of any sum paid for taxes, insurance or installments of principal or interest on a prior lien. If the purchaser is the holder of a lien upon real property other than that under which sale was made, which is superior to the lien of the redemptioner, the redemptioner shall likewise pay the amount of the additional lien, including interest to the date of payment.
SDCL 21-52-14