Mont. Code Ann. § 27-2-506
27-2-506 Existing and future claims
27-2-506 . Existing and future claims. This part applies to claims:
(1) accruing after October 1, 1991; or
(2) asserted in a civil action or proceeding more than 1 year after October 1, 1991, but do not revive a claim barred before October 1, 1991.