concurring, in which NYGAARD, Circuit Judge, joins.
I concur and join in the opinion of the Court, with the exception of Parts III.B.1, III.B.3, and III.C. I write separately because I believe it is unnecessary in this *268case to grapple with the nuances of “legal custody” under New York law.
The threshold question that must be decided, as I see it, is the validity of the custody decree entered by the New York Supreme Court in the 1984 judgment of divorce granted to Brian Bagot, Odiri Ba-got’s father. The New York proceedings were essentially in divorce. The divorce proceedings were instituted by Brian Ba-got. At the time of these proceedings, Frances Wright, his wife, and their children, including Odiri, a minor, resided in Guyana. They did not appear in these proceedings. As for Brian Bagot, he had emigrated to the United States in 1982, and settled in Brooklyn, New York.
The divorce decree consisted of a brief printed form order dissolving the marriage. As an ancillary measure, the decree stated that “Frances Bagot shall have custody of the children of the marriage.” At the time, the children were in Guyana, a foreign country, and in the physical custody of their mother. They did not reside with their father and had not set foot in New York. Thus, although the New York Supreme Court had in rem jurisdiction to enter the judgment of divorce, because Brian Bagot had been residing in New York continuously for more than two years, see N.Y. Dom. Rel. Law § 230(5) (2004), the court had no in personam or subject matter jurisdiction to determine the legal status of Brian Bagot’s children. See Vernon v. Vernon, 296 A.D.2d 186, 191, 746 N.Y.S.2d 284 (N.Y.App.Div.2002); Zwerling v. Zwerling, 167 Misc.2d 782, 636 N.Y.S.2d 595, 598 (N.Y.Sup.Ct.1995); Pavlo v. Pavlo, 137 Misc.2d 418, 520 N.Y.S.2d 991, 993 (N.Y.Sup.Ct.1987).
As Judge Becker points out, the New York courts had jurisdiction to make “child custody determinations only if they can meet the higher standards of the Uniform Child Custody Jurisdiction Act (UCCJA), N.Y. Dom. Rel. Law § 75-d(l) (1999),” repealed by 2001 N.Y. Laws ch. 386. Ante, at 263 & n. 10. The UCCJA was in effect when the New York Supreme Court entered the divorce decree and fixed the status of the children, and was the governing New York law at all times relevant to this appeal.
Under the UCCJA, much more was required before the court could exercise child custody jurisdiction than in rem jurisdiction over one parent for divorce. The New York court could have exercised jurisdiction over Brian Bagot’s minor son only if New York were the home state of the child at the time of the custody proceeding, or if New York had been his home state within six months before the commencement of the proceedings and the child had been absent from the state because of his removal or retention by a person claiming custody or for other reasons. See N.Y. Dom. Rel. Law § 75-d(l)(a). The court also could have had jurisdiction under the UCCJA if it was in the best interest of the child that the court assume jurisdiction because the child and his parents, or the child and at least one parent, had a significant connection with the state and there was within the jurisdiction of the court substantial evidence concerning the child’s present or future care, training, and relationships. See id. § 75-d(l)(b). The court might also have had jurisdiction in the event the child had been abandoned or in certain other situations, none of which are relevant here. See id. § 75 — d(l)(c)—(d).
Thus, for the reasons set forth in Judge Becker’s analysis of the foregoing New York jurisdiction statute, we are in agreement that the undisputed facts of this case “lead inevitably to the legal conclusion that the New York Supreme Court lacked subject matter jurisdiction over the custody determination under § 75-d.” Ante, at *269265. See, e.g., Weyant v. Barnett, 302 A.D.2d 801, 802, 756 N.Y.S.2d 322 (N.Y.App.Div.2003) (approving the dismissal of child custody proceeding for lack of jurisdiction under the UCCJA where “substantial evidence concerning the chib dren’s care, protection, training and relationships does not exist in New York,” the “allegations of emergency [were] insufficient,” and “the children had resided with their mother in North Carolina for more than six years see also McBride v. McBride, 688 So.2d 856, 859 (Ala.Civ.App.1997).
Because there was no valid decree of the New York Supreme Court, or as far as this record shows, any other court, giving custody of Odiri Bagot to Frances Wright, his mother, he was not subject to any decree of court fixing his legal custody when he emigrated to the United States in 1988 and when his father applied for United States citizenship in 1991. I therefore disagree with the Judge Becker that we need to examine the law of New York with regard to parental rights in minor children prior to Brian Bagot’s application for naturalization.
Turning to Odiri Bagot’s legal status in New York in 1991, when his father applied for naturalization, we are informed that, in 1988, when he was fourteen years old, he and his siblings came to live with their father in New York. Due to poor conditions in Guyana, their mother had agreed that it was in the best interests of the children to transfer physical custody of them to their father, while she remained behind in their home country. Odiri’s father provided him with a home, enrolled him in a public school, and otherwise supported him. In 1991, when his father became a naturalized citizen, Odiri Bagot was still a minor, seventeen years old, and still living with his father. As the opinion of the Court concludes, it is clear that his father had actual, consensual physical custody of the boy for derivative citizenship purposes.
Because Odiri Bagot was not born in the United States and had never been naturalized, it is undisputed that his claim of citizenship is derivative upon his father’s naturalization. Citizenship in the United States and naturalization proceedings are federal matters and are governed by the federal Constitution and federal statutes. At the time of that naturalization, the Immigration and Nationality Act provided for derivative citizenship of a child permanently residing in the United States while under the age of eighteen upon the “naturalization of the parent having legal custody of the child when there has been a legal separation of the parents.” 8 U.S.C. § 1432(a)(3), repealed by Child Citizenship Act of 2000, Pub. L. No. 106-395, § 103(a), 114 Stat. 1631. Former § 1432(a)(3) was in effect when Brian Bagot was naturalized and controls this case. See ante, at 257 & n. 3. . ■
In the absence of a judicial decree determining the legal status of a minor child or some other judicial grant of custody, the remaining question in the instant case is whether Brian Bagot’s custody of his son satisfies the “legal custody” requirement of § 1432(a)(3) for derivative citizenship' purposes. The Bureau of Immigration Appeals considered this precise question in making a status determination in Matter of M — , 3 I. & N. Dec. 850, 1950 WL 6650 (BIA 1950). In that case, a child born in Czechoslovakia in 1929 of alien parents was admitted to the United States as a permanent resident in August 1947. The marriage of her parents had been annulled in 1940 and, as in this ease, the child remained abroad with her mother until August 1947. The father came to the United States in 1941 and became a naturalized citizen in 1946. The decree of *270annulment made no provision for the custody of the child. As in this case, the child’s mother orally agreed in 1947 to the father’s assumption of custody of the child. In April 1948, the mother stated in an affidavit that the father had obligated himself since August 1947 to educate and support the child to which the mother consented, and that the daughter would remain with her father.
The BIA held that:
[I]n the absence of judicial determination or judicial or statutory grant of custody in the case of legal separation of the parent[s] of a. person claiming citizenship under section 314(c), the parent having actual uncontested custody is to be regarded as having “legal custody” of the person concerned for the purpose of determining that person’s status under section 314(c).
Matter of M — , 3 I. & N. Dec. at 856. Although Matter of M— is only a decision of a federal agency, it has not been rejected for over a half-century, and has been the subject of approval of the federal courts. See Barthelemy v. Ashcroft, 329 F.3d 1062, 1067 n. 4 (9th Cir.2003) (Where “neither natural parent ... [has] been awarded legal custody of the child by a court ..., the parent with physical control of the child will have a claim to ‘legal custody’ over the child.”); Wedderburn v. INS, 215 F.3d 795, 797 (7th Cir.2000) (citing Matter of M — , approvingly); Charles v. Reno, 117 F.Supp.2d 412, 417-18 (D.N.J.2000) (applying “actual uncontested custody” standard of Matter of M— where no court order or statutory grant of custody existed).
In the absence of a legal custody decree for a minor child, as we have here, an analysis of child custody law in the State of New York is unnecessary and irrelevant. Indeed, Judge Becker also concludes that “we essentially adopt, the entire test of Matter of M— in this case, requiring a judicial decree or, failing that, actual uncontested custody.” Ante, at 263 n. 9.
Judge Becker believes that he is compelled to explore New York law concerning legal custody of a minor child, even in the absence of a legal decree, based on his understanding of Fierro v. Reno, 217 F.3d 1 (1st Cir.2000). However, unlike our situation here, a state probate court in Fierro had issued a valid custody decree. See Fierro, 217 F.3d at 4. Here, there is none. By contrast, in 1991 when Brian Bagot applied for naturalization, the not-uncommon relationship existed where parents consensually agreed upon the physical, uncontested custody of a minor child.
The opinion of the Court ultimately concludes that “it is clear” that Brian Bagot had “legal custody” of his son, Odiri, for derivative citizenship purposes. Ante, at 269. The opinion of the Court also rejects the Respondents’ argument that “legal custody,” like “legal separation,” requires a court decree. Ante, at 270. I fully agree with both propositions.
Accordingly, we agree that when he was naturalized in 1991, Brian Bagot had legal custody of his son, Odiri, for derivative citizenship purposes. Because all other requisites of § 1432(a) were also met, Odi-ri obtained derivative United States citizenship when his father was naturalized. Odiri Bagot, therefore, is not deportable and the Order of the District Court should be reversed and the case remanded to the District Court with instructions to issue a writ of habeas corpus.