dissenting:
The majority thoughtfully explains the authority of various federal government agencies over unaccompanied alien children. But this case does not feature an unaccompanied alien child. This case features an accompanied alien child.
R.M.B. is a child. He is an alien. But he is not unaccompanied. R.M.B.’s mother, Dora Beltran, is here in the United States. She is a lawful permanent resident, J.A. 33, and has been protesting for more than two years that she is available to take custody of R.M.B.
The agency here does not want to release R.M.B. because it thinks that Beltran is an unfit mother. Perhaps she is. But Congress has not empowered the federal Office of Refugee Resettlement to seize children from bad parents. The Office is only authorized to detain alien children whose parents are not available in the United States. Because Beltran is “available to provide care” as defined in statute, the Office has no legal authority to detain R.M.B.
I am not insensitive to the majority’s unstated concern that society is better off with R.M.B.. in government custody. If that is true, any number of state or other federal government authorities may be legally authorized to act. But the question in this case is whether the Office has authority. It does not. I must respectfully dissent.
I.
As the majority notes, Congress has conferred to the Office the authority to detain unaccompanied alien children. Ante, at 733 & n. 9. Congress defines an “unaccompanied alien child” (UAC) as a child who:
(A)has no lawful immigration status in the United States;
(B) has not attained 18 years of age; and
(C) with respect to whom—
(i) there is no parent or legal guardian in the United States; or
(ii) no parent or legal guardian in the United States is available to provide care and physical custody.
6 U.S.C. § 279(g)(2). Thus, to be a UAC an individual must satisfy each of the three prongs: (A), (B), and (C).
R.M.B. satisfies prongs (A) and (B) of the statutory definition: he “has no lawful immigration status” and he “has not attained 18 years of age.” Prong (C) can be satisfied in one of two ways. R.M.B. does not satisfy prong (C) the first way; he has a parent, Beltran, “in the United States.” Whether or not R.M.B. is legally an “unaccompanied alien child” — and, therefore, whether the Office has authority to detain him — thus turns on whether or not he satisfies prong (C) the second way — that is, whether Beltran “is'available to provide care and physical custody.”
Thus far, the majority and I agree. We also agree that in interpreting the UAC statute, we begin with “the plain meaning of the text.” Trejo v. Ryman Hosp. Props., Inc., 795 F.3d 442, 446 (4th Cir. 2015). But in our reading of “available to provide care,” the majority and I part ways. I think the text means just what it says: a child is not unaccompanied in the United States if a parent is available to provide care. Beltran is available to provide care; R.M.B. is not, therefore, unaccompanied.
The majority interprets the same text to mean “capable of providing for the child’s physical and mental well-being.” Ante, at 734. There are several problems with this reading, not the least of which is that it is not what the statutory definition says. This interpretation also reads the key word— “available” — out of the statute; whatever *745gloss the other words place on “available,” that word must play some role. But the more fundamental problem with the majority’s interpretation is that it comes from reading 6 U.S.C. § 279(g)(2)(C)(ii) independent of its statutory context. “In determining the plain meaning of the text, we must consider the broader context of the statute as a whole in light of the cardinal rule that the meaning of statutory language, plain or not, depends on context.” Trejo, 795 F.3d at 446 (quotations omitted). With respect, the majority’s reading does not fit with the text. And it jars with the context.
A.
The majority makes short work of Bel-tran’s statutory argument that her son R.M.B. is not an unaccompanied alien child: three paragraphs in a nearly 50-page opinion. Ante, at 734. And only a portion of those few paragraphs construes the key statutory definition. More is not always better. But in this instance, I think depth brings clarity.
The majority first notes Beltran’s use of a dictionary to define “available” as “easy or possible to get or use.” Ante, at 734 (citing Appellant’s Br. 19). Without disputing this linguistic definition, the majority characterizes its use as equivalent to an argument that the definition in 6 U.S.C. § 279 (g)(2)(C)(ii) “does not include an assessment of a parent’s fitness or suitability as a custodian.” Ante, at 734. The majority reads in such a suitability assessment by emphasizing that the word “available” is followed by the words “to provide care.” Ante, at 734. The majority then goes to a dictionary to expand on the word “care” and, importing its chosen definition, finds that a parent “must be” “available to provide what is necessary for the child’s health, welfare, maintenance, and protection.” Ante, at 734. I might quibble with the particular substituted definition, but regardless, the statute thus construed still asks only if the parent is “available” to provide; the text still “does not include an assessment of a parent’s fitness or suitability as a custodian.” Ante, at 734.
At this point, Beltrán still might prevail under the majority’s analysis. But rather than apply its own reading of the UAC definition and ask whether Beltrán was available to provide for R.M.B., the majority relies on a distinct, non-definitional provision of the statute to conclude that the UAC definition contains an unstated suitability assessment. Specifically, the majority determines that: “a parent who is not ‘capable of providing for the child’s physical and mental well-being’ — as mandated by the suitable custodian requirement of 8 U.S.C. § 1232(c)(3)(A) — is not available to provide what is necessary for the child’s health, welfare, maintenance, and protection.” Ante, at 734. It is from this cross-statute incorporation that the majority reads “an assessment of a parent’s fitness or suitability” into the UAC definition.1
However, the Supreme Court has “stated time and again that courts must presume that a legislature says in a statute what it means and means in a statute what it says there.” Arlington Cent. School Dist. Bd. of Educ. v. Murphy, 548 U.S. 291, 296, 126 S.Ct. 2455, 165 L.Ed.2d 526 (2006). Accord, e.g., Ross v. Blake, 578 U.S. -, *746-, 136 S.Ct. 1850, 195 L.Ed.2d 117 (2016). There is no reason to presume that when Congress defined UACs to exclude alien children who have an available parent in the United States that Congress meant anything different than what it said. The statutory UAC definition does not use the words “assessment,” “fitness,” or “suitability.” And the majority’s reliance on the different language from a non-definitional part of the statute “denies effect to Congress’ textual shift, and therefore ‘runs afoul of the usual rule that when the legislature uses certain language in one part of the statute and different language in another, the court assumes different meanings were intended.’ ” Roberts v. Sea-Land Servs., Inc., — U.S. -, 132 S.Ct. 1350, 1357 n. 5, 182 L.Ed.2d 341 (2012) (quoting Sosa v. Alvarez-Machain, 542 U.S. 692, 711, n.9, 124 S.Ct. 2739, 159 L.Ed.2d 718 (2004)); cf. Meese v. Keene, 481 U.S. 465, 484, 107 S.Ct. 1862, 95 L.Ed.2d 415 (1987) (“It is axiomatic that the statutory definition of the term excludes unstated meanings of that term.”)
Aside from the problematic reliance on the non-definitional language, the majority over-reads the words “to provide care” that follow the word “available.” Those following words are part of the statutory definition, and it is natural to read them as informing the sense in which “available” is used. But it is unnatural to read them to transmute the word Congress used— “available” — into a wholly different word. The alchemy of plain meaning is not so powerful. Rather, those following words speak to situations in which a parent’s availability is limited in a straightforward way. If a parent were, for example, incarcerated, they might be “available to speak on the phone” but likely would not be “available to provide care.”
Of course the Supreme Court’s presumption “that a legislature says in a statute what it means and means in a statute what it says there,” Murphy, 548 U.S. at 296, 126 S.Ct. 2455, is just that: a presumption. It can be overcome. Although I conclude that the plain meaning of “available” is available, my disagreement with the majority on this issue is not solely the result of looking at a statutory word or four and seeing a different meaning. The more fundamental reason that I cannot join in the majority’s reading is that, as discussed below, it simply does not accord with the statutory context.
B.
A laser focus on isolated words risks missing the forest for the trees. One need not accept what I consider the most natural reading of “available to provide care” to reject the majority’s construction. The statutory context readily dispels the notion that myriad federal agencies are required to make 'ad hoc parental suitability determinations in the field.
1.
The repeated use of the acronym “UAC,” although efficient, obscures the precise term that 6 U.S.C. § 279(g)(2) is defining. The words “available to provide care and physical custody” in 6 U.S.C. § 279(g)(2)(C)(ii) help define what makes an individual an “unaccompanied alien child.” Specifically, the words in subsection (ii) define whether an individual is accompanied or not.
The statutory UAC definition has three prongs, one for each of three relevant characteristics. An individual is an “alien” if he or she “has no lawful immigration status in the United States,” id. § 279(g)(2)(A); is a “child” if he or she “has not attained 18 years of age,” id. § 279(g)(2)(B); and is “unaccompanied” if “no parent or legal guardian in the United States is available to provide care and physical custody,” id. § 279(g)(2)(C)(ii). If *747an individual has all three characteristics, he or she is an “unaccompanied alien child.”
It thus strikes me that however we read “available” in prong (C), it must go to the question of whether an alien child is accompanied in the United States or not. As a purely linguistic matter, I do not think ■ that a parent’s “fitness” spéaks to whether the parent is accompanying a child. Put another way, a child can be accompanied by an unfit parent. It is much harder, linguistically and practically, to be accompanied by an unavailable parent.
One additional observation before looking outside of 6 U.S.C. § 279(g)(2): both parts of prong (C) speak broadly of a parent being “in the United States.” This language strongly suggests that in drafting the statute, Congress was concerned with whether a child was accompanied in the sense of having a parent in the territory of the United States, and not accompanied in the sense of having a parent holding the child’s hand at all times. The “in the United States” language is difficult to harmonize with an accompaniment status that changes every time a parent goes to work, drops a child off at school, or runs to the grocery store. It is much easier to read the language in harmony with a legislative concern about, for example, children who cross the border into the United States without their parents.2
This does not mean that a parent is necessarily “available to provide care” simply because she or he is somewhere in the territory of the United States. The first part of prong (C) of the UAC definition sets the baseline that a child is not unaccompanied if they have a “parent or legal guardian in the United States”; the second part of prong (C) acknowledges the reality that although physically present, a parent in the United States may not be “available to provide care and physical custody” as a practical matter. 6 U.S.C. § 279(g)(2)(C). One obvious application, alluded to earlier, would be to a parent who is incarcerated or otherwise in custodial detention in the United States. It would be absurd to conclude that Congress intended the Office to turn away vulnerable children on the basis that they were accompanied by a jailed parent. Another likely application is to parents in the United States whose existence is not known to federal authorities. If a parent refuses to make herself available to take custody of a child — perhaps out of a concern for her own immigration status — Congress could hardly have expected the Office to release the minor on his or her own.
2.
Beyond Section 279(g)(2), the “broader context of the statute,” Trejo, 795 F.3d at *748446, strongly counsels against reading an extra-textual parental fitness assessment into the definition of “unaccompanied.” As the majority observes, “[t]he care and custody of UACs by the government is governed by a legal framework consisting primarily of two statutory provisions — § 279 of Title 6 and § 1232 of Title 8.” Ante at 731. The term “unaccompanied alien child” appears in numerous places in each, and both provisions make explicit that the definition in 6 U.S.C. § 279(g)(2) controls throughout. See 6 U.S.C. § 279(g); 18 U.S.C. § 1232(g). The Office refers to these statutes as “the UAC statutes.” E.g., Appellees’ Br. 33.
A quick skim of the statutes makes plain that the Office’s authority runs only to UACs; every relevant statutory grant of authority to the Office is conditioned on the existence of an unaccompanied alien child. This fact is important, as “an agency literally has no power to act ... unless and until Congress confers power upon it.” New York v. FERC, 535 U.S. 1, 18, 122 S.Ct. 1012, 152 L.Ed.2d 47 (2002) (quoting La. Pub. Serv. Comm’n v. FCC, 476 U.S. 355, 374, 106 S.Ct. 1890, 90 L.Ed.2d 369 (1986)). Like all federal agencies, the Office of Refugee Resettlement is “a creature of statute. It has no constitutional or common law existence or authority, but only those authorities conferred upon it by Congress.” Michigan v. EPA, 268 F.3d 1075, 1081 (D.C. Cir. 2001).
The core statutory authority the Office relies on for the legality of its continued detention of R.M.B. is 8 U.S.C. § 1232(c)(3)(A). See Appellees’ Br. 26 n.4 (“The reason R.M.B. is still in ORR custody is ... the Congressional mandate in 8 U.S.C. § 1232(c)(3)(A).”) The majority refers to this provision as the “suitable custodian requirement.” Ante, at 727. Section 1232(c)(3)(A) provides:
[A]n unaccompanied alien child may not be placed with a person or entity unless the [Secretary] makes a determination that the proposed custodian is capable of providing for the child’s physical and mental well-being.
The Office refuses to “place” R.M.B. with Beltrán because it has determined that Beltrán is incapable and thus not a suitable custodian.
If Beltrán were only to dispute the wisdom of the Office’s determination, my view of the Office’s position might be different. But Beltrán disputes the Office’s authority to make the determination at all. This is why the case is before us on a habeas petition and not, for example, via the Administrative Procedure Act. See 5 U.S.C. § 702. Congress has only conferred to the Office the authority to make placement determinations for unaccompanied alien children: 8 U.S.C. § 1232(c)(3)(A) explicitly states that “an unaccompanied alien child may not be placed.” (emphasis added). If R.M.B. is not unaccompanied, the Office “literally has no power to act” over him, New York, 535 U.S. at 18, 122 S.Ct. 1012, whether it is purporting to detain him, place him, or otherwise.
In my view, the text and structure of 8 U.S.C. § 1232 preclude reading the UAC definition in 6 U.S.C. § 279(g)(2) to include a parental fitness component. The Office’s application of these statutes to R.M.B. and Beltrán is illustrative. Under the majority’s reading, the suitable custodian requirement in Section 1232(c)(3)(A) becomes superfluous: a determination that Beltrán is suitable would simultaneously operate to make her available under the majority’s reading of Section 279(g)(2); this would render R.M.B. not a UAC, making the placement determination both unnecessary and beyond the Office’s authority. In cases in' which a child has a parent in the United States, the majority’s read*749ing makes the UAC determination and the suitable custodian determination redundant. The Supreme Court has admonished:
It is a fundamental canon of statutory construction that the words of a statute must be read in their context and with a view to their place in the overall statutory scheme. A court must therefore interpret the statute as a symmetrical and coherent regulatory scheme and fit, if possible, all parts into a harmonious whole.
FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 133, 120 S.Ct. 1291, 146 L.Ed.2d 121 (2000) (quotations omitted). It is quite possible to fit Section 279(g)(2) and Section 1232(c)(3)(A) into a harmonious whole. Reading the former to enquire of a parent’s availability, and the latter to ask of an alternate custodian’s suitability, reveals a coherent regulatory scheme — one that recognizes that Congress never intended the Office to be making Section 1232(c)(3)(A) determinations for a child whose parent is knocking on the Office’s door.3
Another contextual problem with fitting the majority’s UAC definition into the statutory scheme becomes apparent when considering how R.M.B. wound up in Office custody. As the Office repeatedly reminds the Court, it was Customs and Border Protection (CBP) that first classified R.M.B. as a UAC before transferring him to the Office. The majority correctly holds that we are not concerned here with CBP’s detention authority, because habeas only tests current detention and R.M.B. is currently being detained by the Office. Ante, at 734 n. 10.4
However, this does not make CBP’s involvement irrelevant. The statutory UAC definition in 6 U.S.C. § 279(g)(2) applies to all federal agencies, not just the Office. (Indeed, the Office generally does not take custody of a child in the first instance; it receives custody of children from other federal agencies.) It is axiomatic that “available” has the same meaning when the statute is read by an employee of one federal agency as it does when the same statute is read by an employee of a different federal agency.
The Office tells us that “federal agents who encounter a child ... are tasked with quickly determining whether a child is a UAC and transferring the child to HHS.” Appellees’ Br. 28. Congress mandates each agency to notify HHS of “discovery of an unaccompanied alien child” within 48 hours and, except in exceptional circumstances, transfer custody within 72 hours. See 8 *750U.S.C. § 1232(b). Congress could reasonably expect a federal agent to determine whether a child has a parent in the United States within this time frame. I cannot see how agents could be expected to make parental suitability determinations in this window.
Congress has created a “coherent regulatory scheme,” Brown & Williamson, 529 U.S. at 133, 120 S.Ct. 1291, for minor aliens present in the United States without a parent or legal guardian. The statutes work as a harmonious whole when “available” in 6 U.S.C. § 279(g)(2) is read to mean “available.” By reading “available” to mean something else, the majority turns the UAC definition into a square peg that does not fit into the statutory whole.
C.
It is not only the text of the definition and the context of the statute that I think foreclose the majority’s construction of “available to provide care.” I am also concerned by the necessary consequences of that construction. I do not mean the practical consequences for Beltrán or R.M.B., or anyone else; I mean the consequence that the statutory scheme thus interpreted raises unnecessary constitutional questions.
As the Supreme Court has explained, “when deciding which of two plausible statutory constructions to adopt, a court must consider the necessary consequences of its choice. If one of them would raise a multitude of constitutional problems, the other should prevail — whether or not those constitutional problems pertain to the particular litigant before the Court.” Clark v. Martinez, 543 U.S. 371, 380-81, 125 S.Ct. 716, 160 L.Ed.2d 734 (2005). The majority construes the statutes to permit an administrative agency of the federal government to involuntarily detain a lawful permanent resident’s child if the agency decides that the resident is an unfit parent.5
To be sure, the Constitution does not forbid the government from removing children from unfit parents. However, such an exercise of state power is generally conditioned by significant procedural safeguards. See, e.g., Stanley v. Illinois, 405 U.S. 645, 658, 92 S.Ct. 1208, 31 L.Ed.2d 551 (1972) (holding that “parents are constitutionally entitled to a hearing on their fitness before their children are removed from their custody”). Congress’s power over immigration is very broad, and in this arena Congress “regularly makes rules that would be unacceptable if applied to citizens.” Reno v. Flores, 507 U.S. 292, 305-06, 113 S.Ct. 1439, 123 L.Ed.2d 1 (1993) (quotation omitted). But this power is not absolute, and in these circumstances it confronts constitutional rights that are among the most basic and resistant to government interference: the right “to raise one’s children,” e.g., Stanley, 405 U.S. at 651, 92 S.Ct. 1208, and the right to “freedom from bodily restraint” that “has always been at the core of the liberty protected by the Due Process Clause.” Foucha v. Louisiana, 504 U.S. 71, 80, 112 S.Ct. 1780, 118 L.Ed.2d 437 (1992). Both Beltrán and R.M.B. are entitled to the protections of due process. See Zadvydas v, Davis, 533 U.S. 678, 693, 121 S.Ct. 2491, 150 L.Ed.2d 653 (2001) (collecting cases).
If a federal agency seized a citizen child from a citizen parent without a hearing, under a statute analogous to that here, I am skeptical that such action would sur*751vive constitutional scrutiny. Although the constitutional concerns are decidedly attenuated for aliens, Flores, 507 U.S. at 305-06, 113 S.Ct. 1439, they are significant enough that the majority devotes ten pages to addressing them. Ante, at 739-43. And with regard to Beltran’s procedural due process claim, the majority concludes it must vacate the district court’s holding on the issue and remand for additional proceedings. Ante, at 743.
I do not suggest that all or any portion of 6 U.S.C. § 279 or 8 U.S.C. § 1232 is unconstitutional. I only suggest that there is no need to read those statutes such that their constitutionality is even in question. A chief justification of the canon of constitutional avoidance “is that it allows courts to avoid the decision of constitutional questions. It is a tool for choosing between competing plausible interpretations of a statutory text, resting on the reasonable presumption that Congress did not intend the alternative which raises serious constitutional doubts.” Clark, 543 U.S. at 381, 125 S.Ct. 716. Cf. Zadvydas, 533 U.S. at 682, 121 S.Ct. 2491 (construing an immigration statute “to contain an implicit ‘reasonable time’ limitation” due to “serious constitutional concerns” with the “indefinite detention” of certain aliens).
As I read the statutes here, the federal government may take custody of alien minors who do not have a parent or other legal guardian available in the United States. The constitutional concerns with such a regulatory scheme are minimal. See, e.g., Flores, 507 U.S. at 305, 113 S.Ct. 1439 (“If we harbored any doubts as to the constitutionality of institutional custody over unaccompanied juveniles, they would surely be eliminated as to those juveniles ... who are aliens.”) But as the majority construes these statutes, the constitutional questions are very real. Cf. id. at 302-03, 113 S.Ct. 1439.
A “longstanding principle of judicial restraint requires that courts avoid reaching constitutional questions in advance of the necessity of deciding them.” Camreta v. Greene, 563 U.S. 692, 705, 131 S.Ct. 2020, 179 L.Ed.2d 1118 (2011) (quotation omitted). Cf. Zadvydas, 533 U.S. at 689, 121 S.Ct. 2491 (“We have read significant limitations into other immigration statutes in order to avoid their constitutional invalidation.”) There is no need to decide any constitutional questions here. We need only read the statutes as written.
II.
On my view of the Office’s statutory authority, there is no need to address the other issues reached by the majority. Questions about the full statutory scope of the Office’s authority over UACs, or the constitutionality of that authority in application, are moot in my mind. Because the Office has no statutory authority to detain R.M.B., we should order the Office to stop detaining him.
I note that such an order need not — and perhaps should not — result in R.M.B. being released from all government custody. I detect in the majority opinion, and in the opinion of the district court, a concern about the risk R.M.B. poses to society. Although many of the allegations the government appellees introduce into the record are unsubstantiated, I am under no illusion about R.M.B. I am also not insensitive to the possibility that his best interests may not be served by being released to Beltran.
There are legally authorized processes to address these concerns. For example, if federal or state authorities have probable cause to suspect R.M.B. has committed a crime, he can be arrested. If state child welfare agencies are concerned about Bel-tran’s fitness to exercise custody over *752R.M.B., those agencies have the statutory authority — and perhaps the obligation — to intervene. But just because there may be a valid authority to detain R.M.B., it does not mean that any claimed authority is valid. I conclude that the Office lacks statutory authority over R.M.B. and that the agency’s continued detention of him — now for more than two years — is unlawful.
I respectfully dissent.
. The majority later makes explicit that it is substituting 8 U.S.C. § 1232’s "suitable custodian requirement” in place of 6 U.S.C. § 279’s definition of an “unaccompanied alien child”: "Because the Office’s unsuitability finding establishes that Beltrán is not available to provide care and physical custody of R.M.B., we cannot say that R.M.B.'s detention is based on an erroneous application or interpretation of the UAC definition.” Ante, at 734.
. See Office of Refugee Resettlement, Children Entering the United States Unaccompanied: Introduction (January 30, 2015), http:// www.acf.hhs.gov/programs/orr/resource/ children-entering-the-united-states-unaccompanied-0 (suggesting that "unaccompanied children” are those "who enter the United States ... without a parent”). I note that although it does not appear that our sister circuits have construed the definition, the few decisions that reference 6 U.S.C. § 279(g)(2) appear to assume that UAC status does not turn on a parental fitness assessment. See, e.g., Cortez-Vasquez v. Holder, 440 Fed.Appx. 295, 298 (5th Cir. 2011); Tam-baani v. Attorney Gen. of U.S., 388 Fed.Appx. 131, 134 (3rd Cir. 2010). I also note that the Office does not appear to read the statute as the majority does. The Office’s primary argument is that the federal courts lack jurisdiction to review agency application of the UAC statute; the majority, as do I, rightly rejects this argument. See ante, 730-31. When the Office does take a position on the scope of the statutory definition, it suggests parental proximity, rather than fitness, is the touchstone. See, e.g., Appellees Br. 29 n.7. I presume this is why the Office has not taken custody of those of Beltrán’s other minor children who are aliens.
. The Office appears to concede that its authority ends once an individual ceases to be an "unaccompanied alien child.” It recognizes that its authority ends once R.M.B. "turns eighteen.” Appellees’ Br. 1. It also recognizes that its authority ends if R.M.B. gains "lawful immigration status.” Id. at 40 n.14. In other words, the Office’s custodial authority ends when R.M.B. is either not a "child,” or not an "alien.” The text of the UAC definition provides no indication that custodial authority does not also end when R.M.B. is no longer “unaccompanied.”
. I understand this holding to implicitly reject one of the Office’s alternative arguments; I will explicitly reject it. The Office suggests that once CBP classified R.M.B. as a UAC, the Office was powerless to classify him otherwise. Congress did not give federal agencies discretion to classify individuals as UACs. Congress provided an explicit statutory definition. An individual who satisfies the definition is a UAC and must be treated as such; if the individual does not satisfy the definition, the government has no nebulous discretionary authority to treat the individual as a UAC. If CBP wrongly classified R.M.B. as a UAC in violation of statute, transferring R.M.B. to another federal agency does not cure the violation. R.M.B. is a UAC if 6 U.S.C. § 279(g)(2) says he is, not if the government declares him so. The Office cannot expand its statutory authority by arguing that some other agency violated the statute first.
. Nothing in the majority’s construction would appear to bar the Office from detaining the alien child of a U.S. citizen in the United States. The UAC definition only addresses the child’s immigration status. If Beltrán naturalizes, it has no obvious effect on the operation of 6 U.S.C. § 279(g)(2).