A party or support enforcement agency seeking to modify or to modify and enforce a child support order issued in another state shall register that order in this state in the same manner provided in 40-5-1055 through 40-5-1062 if the order has not been registered. A petition for modification may be filed at the same time as a request for registration or later. The pleading must specify the grounds for modification.
§ 40-5-1063, MCA