Wis. Stat. § 822.22: Exclusive, continuing jurisdiction.

(1) Except as provided in s. 822.24, a court of this state that has made a child custody determination consistent with s. 822.21 or 822.23 has exclusive, continuing jurisdiction over the determination until any of the following occurs:

(a) A court of this state determines that neither the child, nor the child and one parent, nor the child and a person acting as a parent have a significant connection with this state and that substantial evidence is no longer available in this state concerning the child’s care, protection, training, and personal relationships.

(b) A court of this state or a court of another state determines that the child, the child’s parents, and all persons acting as parents do not presently reside in this state.

(2) A court of this state that has made a child custody determination and that does not have exclusive, continuing jurisdiction under this section may modify that determination only if it has jurisdiction to make an initial determination under s. 822.21.