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 Louisiana (LA), 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 can vary, but it generally means a change that would significantly affect the child's best interests. The petition to modify custody is typically filed in the court that issued the original custody order. However, if the child has since moved to 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. An attorney can provide guidance on the specific procedures and evidentiary requirements for filing such a petition in Louisiana.