SDCL § 21-52-20: Amounts payable to junior lien holders.

No person shall be required to pay the amount of a lien junior to his own, but he shall pay to the holder of any junior lien who has made redemption the amount paid by him to make redemption, interest thereon, and any sums advanced by such junior lien holder for the protection of such real property for taxes, insurance, or installments of interest or principal on a prior lien.