Mont. Code Ann. § 72-2-832
72-2-832 Application to existing relationships
72-2-832 . Application to existing relationships. Except as otherwise provided in 72-2-829 , an interest in or power over property existing on October 1, 2019, as to which the time for delivering or filing a disclaimer under law superseded by 72-2-817 through 72-2-833 has not expired may be disclaimed after October 1, 2019.