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 sections 580-601 through 580-608 of this part 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.
N.Y. Family Court Law § 580-609