Either parent may file a petition to modify a child custody order—but usually only when there is a substantial change in circumstances that affects the child (including changes in one or both of the parents’ lives) that justifies the court revisiting and possibly modifying the earlier child custody order.

The petition to modify child custody generally must be filed in the same court in which the parents’ divorce case was decided. But if the child lives in a different county or state, the courts of the county or state where the child lives may be the proper place to file a petition to modify a child custody order.

In New Jersey, either parent has the right to file a petition to modify a child custody order if there is a substantial change in circumstances that affects the child's well-being. This could include significant changes in the life of either parent or the child. The standard for modification is based on the best interests of the child, and the parent seeking the change must demonstrate that the modification is necessary to serve those interests. Typically, the petition to modify custody should be filed in the same court where the original divorce and custody orders were issued. However, if the child has since moved to a different county or state, the petition may need to be filed in the jurisdiction where the child currently resides. New Jersey courts will consider the new jurisdiction appropriate if the child has established a new home state under the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA), which New Jersey has adopted. The UCCJEA dictates that the child's home state, or the state where the child has lived with a parent for at least six consecutive months prior to the commencement of the custody proceeding, typically has jurisdiction to decide custody matters.