28 U.S.C. § 1738A — Full faith and credit given to child custody determinations

(a) A State’s appropriate authorities must enforce, as written, any custody or visitation determination made by another State’s court consistently with this section. They may not modify it except as subsections (f), (g), and (h) allow.
(b) Definitions.—(1) “Child” means a person under 18. (2) “Contestant” means a person, including a parent or grandparent, claiming custody or visitation rights. (3) “Custody determination” means a court judgment, decree, or order about a child’s custody, including permanent, temporary, initial, and modified orders. (4) “Home State” means the State where, immediately before the relevant time, the child lived with both parents, one parent, or a person acting as a parent for at least six consecutive months. For a child under six months old, it is the State where the child lived from birth with such a person. Temporary absences count. (5) “Modification” and “modify” mean a later custody or visitation determination that changes, replaces, supersedes, or otherwise follows an earlier one concerning the same child, whether by the same court or another. (6) “Person acting as a parent” means a nonparent who has physical custody and either received custody from a court or claims a right to custody. (7) “Physical custody” means actual possession and control. (8) “State” means a United States State, the District^* of Columbia, Puerto Rico, or a United States territory or possession. (9) “Visitation determination” means a court judgment, decree, or order about visitation, including permanent, temporary, initial, and modified orders.
(c) A state court’s custody or visitation determination is consistent with this section only if (1) the court has jurisdiction under that State’s law; and (2) one of these is true: (A) the State is the child’s Home State when the case begins, or was the Home State within the previous six months and the child is absent because a contestant removed or kept the child, or for another reason, while a contestant still lives there; (B) no other State appears to qualify under (A), and it is in the child’s best interest for the court to act because the child and parents, or the child and at least one contestant, have a significant connection with the State beyond physical presence and substantial evidence about the child’s present or future care, protection, training, and personal relationships is available there; (C) the child is physically present and has been abandoned, or emergency action is needed because the child, a sibling, or a parent has suffered or faces mistreatment or abuse; (D) no other State appears to qualify under (A), (B), (C), or (E), or another State declined because this State is the better forum, and it is in the child’s best interest for this court to act; or (E) the court has continuing jurisdiction under (d).
(d) A court that made a qualifying determination keeps jurisdiction while it continues to meet (c)(1) and the State remains the residence of the child or any contestant.
(e) Before making a custody or visitation determination, the court must give reasonable notice and an opportunity to be heard to contestants, any parent whose parental rights have not ended, and anyone with physical custody.
(f) A State court may modify another State’s custody determination if it has jurisdiction and the other court no longer has jurisdiction or declined to modify it.
(g) A State court may not exercise jurisdiction over a custody or visitation case begun while another State court is properly exercising jurisdiction over such a determination.
(h) A State court may not modify another State’s visitation determination unless the other court no longer has jurisdiction to modify it or declined to do so.