Mont. Code Ann. § 25-13-805

If the spouse of a judgment debtor redeem, the judgment debtor, within 1 year after the date of sale, may redeem by paying the spouse or the spouse's successors in interest or the sheriff for the benefit of the spouse or the successors in interest of the spouse the amount paid to effect the redemption, with interest thereon at the rate established by the judgment in the action that led to the execution sale from the date of redemption until the date of such payment, together with any taxes or assessments that may have been paid by the spouse or the successors in interest of the spouse, with like interest thereon.