delivered the opinion of the Court.
On January 17, 1951, a New York court granted George Brewer, Jr., a decree of divorce from his wife, now Aida Kovacs. Custody of their five-year-old daughter, Jane, was awarded to George Brewer, Sr., the paternal *605grandfather, pending discharge of Brewer, Jr., from the Navy. As contemplated by the decree, the grandfather removed the child to his home in North Carolina where she has since resided. In November 1954 the mother asked the New York divorce court to modify its decree and award her custody of the child. Although the father and grandfather presented affidavits through counsel challenging the mother’s claim, the court granted custody to her. In modifying its decree the court apparently relied, in part, on findings that the grandfather was ill with heart trouble and diabetes and that the living accommodations which he was able to provide for the child were not as suitable as those then offered by the mother.
The grandfather refused to surrender the child, but the mother took no steps to enforce her custody award until February 1956 — 14 months after the decree had been modified. At that time she brought the present action in a North Carolina state court to secure the child.1 She offered a certified copy of the New York decree and asserted that it was “entitled to full faith and credit in- the courts of North Carolina except as to matters showing changed circumstances since the date of such decree.” The father and grandfather again challenged her right to the child. They presented numerous affidavits attesting to facts which they argued demonstrated that the child’s best interests would be served by leaving her in North Carolina with the grandparents. Many of these facts had been presented to the New York court at the time the divorce decree was modified, but new evidence was also offered concerning the child’s surround*606ings, her school and church experiences and her life in general, particularly with reference to the period that had elapsed between the time when the divorce court modified its decree and the date of the North Carolina proceedings.2
After hearing the case on affidavits, stipulations and the pleadings, the trial court made numerous findings. Among other things, it determined that for more than a year immediately preceding the hearing the grandfather had required no medical care for heart or diabetic ailments and was able to work and to properly care for his granddaughter. The court also found that a 17-year-old stepson, who had been residing in the grandfather’s home at the time the New York decree was modified, had moved from the home thus leaving more space for the remaining occupants and giving the grandfather a better opportunity to provide for the grandchild. On the basis of these and other findings the trial court concluded that it was “not bound by or required to give effect to the decree of the Court of the State of New York made in 1954” and that the welfare of the child demanded that she remain under the grandfather’s custody in the environment to which she had become accustomed.
On appeal the North Carolina Supreme Court approved the trial court’s findings, and without specifying any particular reason upheld its “conclusion of law.” The court then went on to declare, seemingly as an alternative ground of decision, that the New York decree was not binding because the divorce court had no jurisdiction to modify its original custody award after the child had become a resident and domiciliary of North Carolina. 245 N. C. 630, 97 S. E. 2d 96. We granted *607certiorari to consider the claim that the North Carolina courts had failed to give full faith and credit to the judicial proceedings of another State. 355 U. S. 810.
In this Court the petitioner, Mrs. Kovacs, contends (1) that the New York divorce court had jurisdiction to modify its decree by awarding her custody of the child, (2) that in any event the question of jurisdiction was res judicata in the North Carolina courts because both the father and grandfather had appeared in the New York proceeding, and (3) that the North Carolina courts failed to give the custody decree, as modified, the faith and credit required by the Federal Constitution and statute.3 She argues that the North Carolina courts were obligated to give the custody decree the same effect as it had in New York, a question which we reserved in New York ex rel. Halvey v. Halvey, 330 U. S. 610, 615-616. As presented, the case obviously raises difficult and important questions of constitutional law, questions which we should postpone deciding as long as a reasonable alternative exists.4
Whatever effect the Full Faith and Credit Clause may have with respect to custody decrees, it is clear, as the Court stated in Halvey, “that the State of the forum has at least as much leeway to disregard the judgment, to qualify it, or to depart from it as does the State where it was rendered.” 330 U. S., at 615. Petitioner concedes *608that a custody decree is not res judicata in New York if changed circumstances call for a different arrangement to protect the child’s health and welfare.5 In the courts below the question of changed circumstances was raised in the pleadings, considerable evidence was introduced on that issue, and the trial court made a number of findings which demonstrated that the facts material to the proper custody of the child were no longer the same in 1956 as in 1954 when the New York decree was modified. And though it is not clear from the opinion of the North Carolina Supreme Court, it may be, particularly in view of this background, that it intended to decide the case, at least alternatively, on that basis. Under all the circumstances we think it advisable to remand to the North Carolina courts for clarification, and, if they have not already decided, so they may have an opportunity to determine the issue of changed circumstances. Cf. Minnesota v. National Tea Co., 309 U. S. 551; Spector Motor Co. v. McLaughlin, 323 U. S. 101, 105. If those courts properly find that changed conditions make it to the child’s best interest for the grandfather to have custody, decision of the constitutional questions now before us would be unnecessary. Those questions we explicitly reserve without expressly or impliedly indicating any views about them.
The judgment of the Supreme Court of North Carolina is vacated and the cause is remanded for further proceedings not inconsistent with this opinion.
It is so ordered.
Under North Carolina law “custody of children of parents who have been divorced outside of North Carolina . . . may be determined in a special proceeding instituted by either of said parents N. C. Gen. Stat. Ann., 1950, § 50-Í3.
Unlike the situation in the New York modification proceeding, the child, father and grandfather were all present before the North Carolina court.
Art. IV, § 1, declares: “Full Faith and Credit shall be given in each State to the public Acts, Records, and judicial Proceedings of every other State. And the Congress may by general Laws prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof.” By statute Congress has provided that judgments “shall have the same full faith and credit in every court within the United States and its Territories and Possessions as they have by law or usage in the courts of such State, Territory or Possession from which they are taken.” 28 U. S. C. § 1738.
This approach is reinforced here by the fact that neither the father nor the grandfather appeared or submitted a brief in this Court in support of their right to custody.
There is some indication that in New York a local custody decree may be modified whenever the best interest of the child demands, whether there have been changed circumstances or not. See, e. g., 6A Gilbert-Bliss’ N. Y. Civ. Prac., 1944, § 1170. Cf. Bachman v. Mejias, 1 N. Y. 2d 575, 580, 136 N. E. 2d 866, 868; Sutera v. Sutera, 1 App. Div. 2d 356, 358, 150 N. Y. S. 2d 448, 451-452.