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 Kentucky, either parent has the right to file a petition to modify a child custody order if there has been 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 what constitutes a substantial change in circumstances can vary, but it generally means a change that would significantly affect the child's current living situation. The petition to modify custody must typically be filed in the same court where the original divorce and custody decisions were made. However, if the child has since moved and now resides in a different county or state, the petition may need to be filed in the court that has jurisdiction over the child's new residence. It's important to note that the court will always prioritize the best interests of the child when considering any modifications to custody arrangements.