28 U.S.C. § 1738B — Full faith and credit for child support orders

(a) General rule.—Each State’s appropriate authorities (1) must enforce, as written, a child-support order made consistently with this section by another State’s court, and (2) may seek or make a modification only as subsections (e), (f), and (i) permit.
(b) Definitions.—(1) “Child” means a person under 18, or a person 18 or older for whom a State law has issued a child-support order. (2) “Child’s State” means where the child lives. (3) “Child’s home State” means where the child lived with a parent or person acting as parent for at least six consecutive months immediately before a support petition or comparable pleading was filed; for a child under six months, it means where the child lived from birth with such a person. Temporary absence counts. (4) “Child support” means money payments, continuing support, arrears, or a benefit for the child, including health insurance, child-care, and education expenses. (5) “Child support order” means a court judgment, decree, or order requiring periodic or lump-sum support payments, including permanent, temporary, initial, and modified orders. (6) “Contestant” means a person, including a parent, who claims support, is a party to a proceeding that may produce an order, or is subject to one; it also includes a State or political subdivision assigned the right to support. (7) “Court” means a State court or administrative agency^* authorized to set or modify support. (8) “Modification” means a later change to an order affecting its amount, scope, or duration. (9) “State” includes a United States State, the District^* of Columbia, Puerto Rico, United States territories and possessions, and “Indian country” as defined in section 1151 of title 18.
(c) Requirements.—An order is consistent with this section only if the issuing court, under its State’s law and subsections (e), (f), and (g), has subject-matter jurisdiction and personal jurisdiction over the contestants, and the contestants received reasonable notice and an opportunity to be heard.
(d) Continuing jurisdiction.—A State court that issued a qualifying order has continuing, exclusive jurisdiction if the State is the child’s State or the residence of an individual contestant, or the parties agreed in a record or open court that the State’s tribunal may keep jurisdiction to modify. This ends if another State properly modifies the order under (e) and (f).
(e) Modification.—A State court may modify another State’s order if it has jurisdiction under (i), and either (A) the original State no longer has continuing, exclusive jurisdiction because it is no longer the child’s State or an individual contestant’s residence and the parties did not consent to continued jurisdiction, or (B) every individual contestant gave written consent to the continuing-jurisdiction State for another State’s court to modify and take continuing, exclusive jurisdiction.
(f) Which order is recognized.—(1) If only one court issued an order, that order controls. (2) If multiple courts issued orders for the same obligor and child, and only one has continuing, exclusive jurisdiction, that order controls. (3) If more than one has such jurisdiction, an order from the child’s current home State controls; if none was issued there, the newest order controls. (4) If none has such jurisdiction, a court with jurisdiction over the parties must issue the controlling order. (5) The court whose order controls has continuing, exclusive jurisdiction under (d).
(g) A State that lost continuing, exclusive jurisdiction may still enforce nonmodifiable obligations and unpaid obligations that accrued before another State modified the order under (e) and (f).
(h) Choice of law.—(1) The forum State’s law applies to proceedings to establish, modify, or enforce an order, except as paragraphs (2) and (3) provide. (2) To interpret an order, including the duration of current payments and other support duties, the court uses the law of the issuing State. (3) To enforce arrears, the court uses the longer limitation period of the forum State or issuing State.
(i) Registration for modification.—If no individual contestant or child lives in the issuing State, the party or support-enforcement agency seeking to modify, or modify and enforce, an order from another State must register it in a State with jurisdiction over the nonmoving party for modification.