(Slip Opinion)
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` OCTOBER TERM, 2012
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`Syllabus
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`1
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` NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
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`
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` being done in connection with this case, at the time the opinion is issued.
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`
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` The syllabus constitutes no part of the opinion of the Court but has been
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` prepared by the Reporter of Decisions for the convenience of the reader.
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` See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.
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`SUPREME COURT OF THE UNITED STATES
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` Syllabus
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` OXFORD HEALTH PLANS LLC v. SUTTER
`
`
`CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
`
`THE THIRD CIRCUIT
` No. 12–135. Argued March 25, 2013—Decided June 10, 2013
`
`Respondent Sutter, a pediatrician, provided medical services to peti-
`
`tioner Oxford Health Plans’ insureds under a fee-for-services contract
`that required binding arbitration of contractual disputes. He none-
`theless filed a proposed class action in New Jersey Superior Court, al-
`leging that Oxford failed to fully and promptly pay him and other
`
`physicians with similar Oxford contracts. On Oxford’s motion, the
`court compelled arbitration. The parties agreed that the arbitrator
`should decide whether their contract authorized class arbitration,
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`and he concluded that it did. Oxford filed a motion in federal court to
`vacate the arbitrator’s decision, claiming that he had “exceeded [his]
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`powers” under §10(a)(4) of the Federal Arbitration Act (FAA), 9
`U. S. C. §1 et. seq. The District Court denied the motion, and the
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`Third Circuit affirmed.
`
`After this Court decided Stolt-Nielsen S. A. v. AnimalFeeds Int’l
`
`
`
`
`Corp., 559 U. S. 662—holding that an arbitrator may employ class
`procedures only if the parties have authorized them—the arbitrator
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`reaffirmed his conclusion that the contract approves class arbitration.
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`Oxford renewed its motion to vacate that decision under §10(a)(4).
`The District Court denied the motion, and the Third Circuit affirmed.
`Held: The arbitrator’s decision survives the limited judicial review al-
`lowed by §10(a)(4). Pp. 4−9.
`
`
`(a) A party seeking relief under §10(a)(4) bears a heavy burden. “It
`is not enough . . . to show that the [arbitrator] committed an error—
`
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`or even a serious error.” Stolt-Nielsen, 559 U. S., at 671. Because the
`parties “bargained for the arbitrator’s construction of their agree-
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`ment,” an arbitral decision “even arguably construing or applying the
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`contract” must stand, regardless of a court’s view of its (de)merits.
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`Eastern Associated Coal Corp. v. Mine Workers, 531 U. S. 57, 62.
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`2
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`OXFORD HEALTH PLANS LLC v. SUTTER
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`Syllabus
`Thus, the sole question on judicial review is whether the arbitrator
`interpreted the parties’ contract, not whether he construed it correct-
`ly. Here, the arbitrator twice did what the parties asked: He consid-
`ered their contract and decided whether it reflected an agreement to
`permit class proceedings. That suffices to show that he did not ex-
`ceed his powers under §10(a)(4). Pp. 4−6.
`(b) Stolt-Neilsen does not support Oxford’s contrary view. There,
`the parties stipulated that they had not reached an agreement on
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`class arbitration, so the arbitrators did not construe the contract, and
`did not identify any agreement authorizing class proceedings. This
`Court thus found not that they had misinterpreted the contract but
`that they had abandoned their interpretive role. Here, in stark con-
`trast, the arbitrator did construe the contract, and did find an
`agreement to permit class arbitration. So to overturn his decision,
`this Court would have to find that he misapprehended the parties’ in-
`tent. But §10(a)(4) bars that course: It permits courts to vacate an
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`arbitral decision only when the arbitrator strayed from his delegated
`task of interpreting a contract, not when he performed that task
`poorly. Oxford’s remaining arguments go to the merits of the arbitra-
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`tor’s contract interpretation and are thus irrelevant under §10(a)(4).
`Pp. 6−9.
`675 F. 3d 215, affirmed.
`KAGAN, J., delivered the opinion for a unanimous Court. ALITO, J.,
`
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`filed a concurring opinion, in which THOMAS, J., joined.
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` Cite as: 569 U. S. ____ (2013)
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`Opinion of the Court
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`1
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` NOTICE: This opinion is subject to formal revision before publication in the
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` preliminary print of the United States Reports. Readers are requested to
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` notify the Reporter of Decisions, Supreme Court of the United States, Wash-
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` ington, D. C. 20543, of any typographical or other formal errors, in order
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` that corrections may be made before the preliminary print goes to press.
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`SUPREME COURT OF THE UNITED STATES
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`_________________
`
` No. 12–135
`_________________
` OXFORD HEALTH PLANS LLC, PETITIONER v.
`
`
`JOHN IVAN SUTTER
`
`ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
`
`
`APPEALS FOR THE THIRD CIRCUIT
`
`[June 10, 2013]
`
`JUSTICE KAGAN delivered the opinion of the Court.
`Class arbitration is a matter of consent: An arbitrator
`
`may employ class procedures only if the parties have au-
`thorized them. See Stolt-Nielsen S. A. v. AnimalFeeds
`Int’l Corp., 559 U. S. 662, 684 (2010). In this case, an
`arbitrator found that the parties’ contract provided for
`class arbitration. The question presented is whether in
`doing so he “exceeded [his] powers” under §10(a)(4) of the
`Federal Arbitration Act (FAA or Act), 9 U. S. C. §1 et seq.
`
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`We conclude that the arbitrator’s decision survives the
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`limited judicial review §10(a)(4) allows.
`I
`Respondent John Sutter, a pediatrician, entered into a
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`contract with petitioner Oxford Health Plans, a health in-
`surance company. Sutter agreed to provide medical care
`to members of Oxford’s network, and Oxford agreed to pay
`for those services at prescribed rates. Several years later,
`Sutter filed suit against Oxford in New Jersey Superior
`Court on behalf of himself and a proposed class of other
`New Jersey physicians under contract with Oxford. The
`complaint alleged that Oxford had failed to make full and
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`OXFORD HEALTH PLANS LLC v. SUTTER
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`Opinion of the Court
`prompt payment to the doctors, in violation of their agree-
`ments and various state laws.
`
`Oxford moved to compel arbitration of Sutter’s claims,
`relying on the following clause in their contract:
`“No civil action concerning any dispute arising under
`this Agreement shall be instituted before any court,
`and all such disputes shall be submitted to final and
`binding arbitration in New Jersey, pursuant to the
`rules of the American Arbitration Association with
`one arbitrator.” App. 15–16.
`The state court granted Oxford’s motion, thus referring
`the suit to arbitration.
`
`The parties agreed that the arbitrator should decide
`whether their contract authorized class arbitration, and
`he determined that it did. Noting that the question
`turned on “construction of the parties’ agreement,” the
`arbitrator focused on the text of the arbitration clause
`quoted above. Id., at 30. He reasoned that the clause sent
`to arbitration “the same universal class of disputes” that it
`barred the parties from bringing “as civil actions” in court:
`The “intent of the clause” was “to vest in the arbitration
`process everything that is prohibited from the court pro-
`
`cess.” Id., at 31. And a class action, the arbitrator contin-
`ued, “is plainly one of the possible forms of civil action that
`
`could be brought in a court” absent the agreement. Ibid.
`Accordingly, he concluded that “on its face, the arbitration
`clause . . . expresses the parties’ intent that class arbitra-
`tion can be maintained.” Id., at 32.
`
`
`Oxford filed a motion in federal court to vacate the
`arbitrator’s decision on the ground that he had “exceeded
`[his] powers” under §10(a)(4) of the FAA. The District
`Court denied the motion, and the Court of Appeals for
`the Third Circuit affirmed. See 05–CV–2198, 2005 WL
`6795061 (D NJ, Oct. 31, 2005), aff ’d, 227 Fed. Appx. 135
`(2007).
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`3
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` Cite as: 569 U. S. ____ (2013)
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`Opinion of the Court
`While the arbitration proceeded, this Court held in
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`Stolt-Nielsen that “a party may not be compelled under
`the FAA to submit to class arbitration unless there is a
`
`contractual basis for concluding that the party agreed to
`do so.” 559 U. S., at 684. The parties in Stolt-Nielsen
`had stipulated that they had never reached an agreement
`on class arbitration. Relying on §10(a)(4), we vacated the
`arbitrators’ decision approving class proceedings because,
`in the absence of such an agreement, the arbitrators had
`“simply . . . imposed [their] own view of sound policy.” Id.,
`at 672.
`
`
`
`Oxford immediately asked the arbitrator to reconsider
`his decision on class arbitration in light of Stolt-Nielsen.
`The arbitrator issued a new opinion holding that Stolt-
`Nielsen had no effect on the case because this agreement
`authorized class arbitration. Unlike in Stolt-Nielsen, the
`arbitrator explained, the parties here disputed the mean-
`ing of their contract; he had therefore been required “to
`construe the arbitration clause in the ordinary way to
`glean the parties’ intent.” App. 72. And in performing
`that task, the arbitrator continued, he had “found that
`the arbitration clause unambiguously evinced an intention
`to allow class arbitration.” Id., at 70. The arbitrator con-
`
`cluded by reconfirming his reasons for so construing the
`clause.
`
`
`Oxford then returned to federal court, renewing its
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`effort to vacate the arbitrator’s decision under §10(a)(4).
`Once again, the District Court denied the motion, and the
`Third Circuit affirmed. The Court of Appeals first under-
`scored the limited scope of judicial review that §10(a)(4)
`
`allows: So long as an arbitrator “makes a good faith at-
`tempt” to interpret a contract, “even serious errors of law
`or fact will not subject his award to vacatur.” 675 F. 3d
`215, 220 (2012). Oxford could not prevail under that
`standard, the court held, because the arbitrator had “en-
`
`deavored to give effect to the parties’ intent” and “articu-
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`OXFORD HEALTH PLANS LLC v. SUTTER
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`Opinion of the Court
`late[d] a contractual basis for his decision.” Id., at
`223–224. Oxford’s objections to the ruling were “simply
`dressed-up arguments that the arbitrator interpreted its
`agreement erroneously.” Id., at 224.
`
`We granted certiorari, 568 U. S. ___ (2012), to address
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`a circuit split on whether §10(a)(4) allows a court to vacate
`an arbitral award in similar circumstances.1 Holding that
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`it does not, we affirm the Court of Appeals.
`II
`
`Under the FAA, courts may vacate an arbitrator’s deci-
`
`
`sion “only in very unusual circumstances.” First Options
`of Chicago, Inc. v. Kaplan, 514 U. S. 938, 942 (1995).
`That limited judicial review, we have explained, “main-
`tain[s] arbitration’s essential virtue of resolving disputes
`straightaway.” Hall Street Associates, L. L. C. v. Mattel,
`Inc., 552 U. S. 576, 588 (2008). If parties could take
`“full-bore legal and evidentiary appeals,” arbitration would
`become “merely a prelude to a more cumbersome and time-
`consuming judicial review process.” Ibid.
`Here, Oxford invokes §10(a)(4) of the Act, which author-
`
`izes a federal court to set aside an arbitral award “where
`the arbitrator[] exceeded [his] powers.” A party seeking
`relief under that provision bears a heavy burden. “It is
`not enough . . . to show that the [arbitrator] committed an
`error—or even a serious error.” Stolt-Nielsen, 559 U. S.,
`at 671. Because the parties “bargained for the arbitra-
`tor’s construction of their agreement,” an arbitral decision
`“even arguably construing or applying the contract” must
`stand, regardless of a court’s view of its (de)merits. East-
`ern Associated Coal Corp. v. Mine Workers, 531 U. S. 57,
`62 (2000) (quoting Steelworkers v. Enterprise Wheel & Car
`
`
`——————
` 1Compare 675 F. 3d 215 (CA3 2012) (case below) (vacatur not proper),
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`
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` and Jock v. Sterling Jewelers Inc., 646 F. 3d 113 (CA2 2011) (same),
` with Reed v. Florida Metropolitan Univ., Inc., 681 F. 3d 630 (CA5 2012)
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`(vacatur proper).
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`4
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`Cite as: 569 U. S. ____ (2013)
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`Opinion of the Court
`Corp., 363 U. S. 593, 599 (1960); Paperworkers v. Misco,
`Inc., 484 U. S. 29, 38 (1987); internal quotation marks
`omitted). Only if “the arbitrator act[s] outside the scope
`of his contractually delegated authority”—issuing an
`
`
`award that “simply reflect[s] [his] own notions of [economic]
`justice” rather than “draw[ing] its essence from the con-
`tract”—may a court overturn his determination. Eastern
`Associated Coal, 531 U. S., at 62 (quoting Misco, 484 U. S.,
`at 38). So the sole question for us is whether the arbitra-
`tor (even arguably) interpreted the parties’ contract, not
`
`whether he got its meaning right or wrong.2
`And we have already all but answered that question just
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`by summarizing the arbitrator’s decisions, see supra, at 2–
`3; they are, through and through, interpretations of the
`parties’ agreement. The arbitrator’s first ruling recited
`the “question of construction” the parties had submitted
`to him: “whether [their] Agreement allows for class action
`arbitration.” App. 29–30. To resolve that matter, the
`arbitrator focused on the arbitration clause’s text, analyz-
`——————
` 2We would face a different issue if Oxford had argued below that the
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` availability of class arbitration is a so-called “question of arbitrability.”
`
`Those questions—which “include certain gateway matters, such as
`whether parties have a valid arbitration agreement at all or whether
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` a concededly binding arbitration clause applies to a certain type of
`controversy”—are presumptively for courts to decide. Green Tree
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` Financial Corp. v. Bazzle, 539 U. S. 444, 452 (2003) (plurality opinion).
`A court may therefore review an arbitrator’s determination of such a
`matter de novo absent “clear[] and unmistakabl[e]” evidence that the
`parties wanted an arbitrator to resolve the dispute. AT&T Technolo-
`gies, Inc. v. Communications Workers, 475 U. S. 643, 649 (1986). Stolt-
`
`
`Nielsen made clear that this Court has not yet decided whether the
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`availability of class arbitration is a question of arbitrability. See 559
`
`
`U. S., at 680. But this case gives us no opportunity to do so because
`Oxford agreed that the arbitrator should determine whether its con-
`tract with Sutter authorized class procedures. See Brief for Petitioner
`
`
`38, n. 9 (conceding this point). Indeed, Oxford submitted that issue to
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`the arbitrator not once, but twice—and the second time after Stolt-
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`Nielsen flagged that it might be a question of arbitrability.
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`OXFORD HEALTH PLANS LLC v. SUTTER
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`Opinion of the Court
`ing (whether correctly or not makes no difference) the
`scope of both what it barred from court and what it sent
`to arbitration. The arbitrator concluded, based on that
`
`textual exegesis, that the clause “on its face . . . expresses
`the parties’ intent that class action arbitration can be
`maintained.” Id., at 32. When Oxford requested reconsid-
`eration in light of Stolt-Nielsen, the arbitrator explained
`that his prior decision was “concerned solely with the par-
`ties’ intent as evidenced by the words of the arbitration
`clause itself.” App. 69. He then ran through his textual
`analysis again, and reiterated his conclusion: “[T]he text of
`
`the clause itself authorizes” class arbitration. Id., at 73.
`Twice, then, the arbitrator did what the parties had asked:
`He considered their contract and decided whether it re-
`
`flected an agreement to permit class proceedings. That
`suffices to show that the arbitrator did not “exceed[ ] [his]
`powers.” §10(a)(4).
`
`Oxford’s contrary view relies principally on Stolt-
`Nielsen. As noted earlier, we found there that an arbitra-
`
`tion panel exceeded its powers under §10(a)(4) when it
`ordered a party to submit to class arbitration. See supra,
`at 3. Oxford takes that decision to mean that “even the
`‘high hurdle’ of Section 10(a)(4) review is overcome when
`an arbitrator imposes class arbitration without a sufficient
`contractual basis.” Reply Brief 5 (quoting Stolt-Nielsen,
`559 U. S., at 671). Under Stolt-Nielson, Oxford asserts, a
`court may thus vacate “as ultra vires” an arbitral decision
`like this one for misconstruing a contract to approve class
`proceedings. Reply Brief 7.
`
`But Oxford misreads Stolt-Nielsen: We overturned the
`arbitral decision there because it lacked any contractual
`basis for ordering class procedures, not because it lacked,
`in Oxford’s terminology, a “sufficient” one. The parties in
`Stolt-Nielsen had entered into an unusual stipulation that
`
`they had never reached an agreement on class arbitration.
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`See 559 U. S., at 668–669, 673. In that circumstance, we
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`7
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` Cite as: 569 U. S. ____ (2013)
`
`Opinion of the Court
`noted, the panel’s decision was not—indeed, could not
`have been—“based on a determination regarding the
`
`parties’ intent.” Id., at 673, n. 4; see id., at 676 (“Th[e]
`stipulation left no room for an inquiry regarding the par-
`ties’ intent”). Nor, we continued, did the panel attempt to
`ascertain whether federal or state law established a “de-
`fault rule” to take effect absent an agreement. Id., at 673.
`Instead, “the panel simply imposed its own conception of
`sound policy” when it ordered class proceedings. Id., at
`675. But “the task of an arbitrator,” we stated, “is to
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`interpret and enforce a contract, not to make public policy.”
`Id., at 672. In “impos[ing] its own policy choice,” the
`panel “thus exceeded its powers.” Id., at 677.
`
`The contrast with this case is stark. In Stolt-Nielsen,
`the arbitrators did not construe the parties’ contract, and
`did not identify any agreement authorizing class proceed-
`ings. So in setting aside the arbitrators’ decision, we
`found not that they had misinterpreted the contract, but
`that they had abandoned their interpretive role. Here, the
`arbitrator did construe the contract (focusing, per usual,
`on its language), and did find an agreement to permit
`class arbitration. So to overturn his decision, we would
`have to rely on a finding that he misapprehended the par-
`
`ties’ intent. But §10(a)(4) bars that course: It permits
`courts to vacate an arbitral decision only when the arbi-
`trator strayed from his delegated task of interpreting a
`contract, not when he performed that task poorly. Stolt-
`Nielsen and this case thus fall on opposite sides of the line
`that §10(a)(4) draws to delimit judicial review of arbitral
`
`decisions.
`
`The remainder of Oxford’s argument addresses merely
`the merits: The arbitrator, Oxford contends at length,
`badly misunderstood the contract’s arbitration clause. See
`Brief for Petitioner 21–28. The key text, again, goes as
`follows: “No civil action concerning any dispute arising
`under this Agreement shall be instituted before any court,
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`8
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`OXFORD HEALTH PLANS LLC v. SUTTER
`
`Opinion of the Court
`and all such disputes shall be submitted to final and bind-
`ing arbitration.” App. 15–16. The arbitrator thought that
`clause sent to arbitration all “civil action[s]” barred from
`court, and viewed class actions as falling within that
`
`category. See supra, at 2. But Oxford points out that the
`provision submits to arbitration not any “civil action[s],”
`
`but instead any “dispute arising under” the agreement.
`And in any event, Oxford claims, a class action is not a
`form of “civil action,” as the arbitrator thought, but merely
`a procedural device that may be available in a court. At
`bottom, Oxford maintains, this is a garden-variety arbi-
`tration clause, lacking any of the terms or features that
`would indicate an agreement to use class procedures.
`
`We reject this argument because, and only because, it is
`not properly addressed to a court. Nothing we say in this
`opinion should be taken to reflect any agreement with the
`arbitrator’s contract interpretation, or any quarrel with
`Oxford’s contrary reading. All we say is that convincing a
`court of an arbitrator’s error—even his grave error—is not
`enough. So long as the arbitrator was “arguably constru-
`ing” the contract—which this one was—a court may not
`correct his mistakes under §10(a)(4). Eastern Associated
`
`Coal, 531 U. S., at 62 (internal quotation marks omitted).
`The potential for those mistakes is the price of agreeing
`to arbitration. As we have held before, we hold again: “It
`is the arbitrator’s construction [of the contract] which was
`bargained for; and so far as the arbitrator’s decision con-
`cerns construction of the contract, the courts have no
`business overruling him because their interpretation of
`the contract is different from his.” Enterprise Wheel, 363
`U. S. at 599. The arbitrator’s construction holds, however
`good, bad, or ugly.
`
`
`In sum, Oxford chose arbitration, and it must now live
`with that choice. Oxford agreed with Sutter that an arbi-
`trator should determine what their contract meant, in-
`cluding whether its terms approved class arbitration. The
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`9
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`It is so ordered.
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` Cite as: 569 U. S. ____ (2013)
`
`Opinion of the Court
`arbitrator did what the parties requested: He provided an
`
`interpretation of the contract resolving that disputed
`issue. His interpretation went against Oxford, maybe
`mistakenly so. But still, Oxford does not get to rerun
`the matter in a court. Under §10(a)(4), the question for a
`judge is not whether the arbitrator construed the parties’
`contract correctly, but whether he construed it at all.
`Because he did, and therefore did not “exceed his powers,”
`
`we cannot give Oxford the relief it wants. We accordingly
`affirm the judgment of the Court of Appeals.
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`

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` Cite as: 569 U. S. ____ (2013)
`
` ALITO, J., concurring
`
`
`SUPREME COURT OF THE UNITED STATES
`
`1
`
`_________________
`
` No. 12–135
`_________________
` OXFORD HEALTH PLANS LLC, PETITIONER v.
`
`
`
`JOHN IVAN SUTTER
`
`ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
`
`
`APPEALS FOR THE THIRD CIRCUIT
`
`[June 10, 2013]
`
`JUSTICE ALITO, with whom JUSTICE THOMAS joins,
`
`
`
`concurring.
`
`As the Court explains, “[c]lass arbitration is a matter of
`consent,” ante, at 1, and petitioner consented to the arbi-
`trator’s authority by conceding that he should decide in
`the first instance whether the contract authorizes class
`arbitration. The Court accordingly refuses to set aside the
`arbitrator’s ruling because he was “‘arguably construing
`. . . the contract’” when he allowed respondent to proceed
`
`on a classwide basis. Ante, at 8 (quoting Eastern Associated
`
`Coal Corp. v. Mine Workers, 531 U. S. 57, 62 (2000)).
`
`Today’s result follows directly from petitioner’s concession
`and the narrow judicial review that federal law allows in
`arbitration cases. See 9 U. S. C. §10(a).
`
`But unlike petitioner, absent members of the plaintiff
`class never conceded that the contract authorizes the ar-
`bitrator to decide whether to conduct class arbitration.
`It doesn’t. If we were reviewing the arbitrator’s interpre-
`
`tation of the contract de novo, we would have little trouble
`concluding that he improperly inferred “[a]n implicit
`agreement to authorize class-action arbitration . . . from
`the fact of the parties’ agreement to arbitrate.” Stolt-
`Nielsen S. A. v. AnimalFeeds Int’l Corp., 559 U. S. 662,
`685 (2010).
`
`With no reason to think that the absent class members
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`

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`OXFORD HEALTH PLANS LLC v. SUTTER
`
` ALITO, J., concurring
`
`
`ever agreed to class arbitration, it is far from clear that
`
`they will be bound by the arbitrator’s ultimate resolution
`of this dispute. Arbitration “is a matter of consent, not
`coercion,” Volt Information Sciences, Inc. v. Board of Trus-
`tees of Leland Stanford Junior Univ., 489 U. S. 468, 479
`(1989), and the absent members of the plaintiff class have
`not submitted themselves to this arbitrator’s authority in
`any way. It is true that they signed contracts with arbi-
`tration clauses materially identical to those signed by the
`plaintiff who brought this suit. But an arbitrator’s erro-
`neous interpretation of contracts that do not authorize
`class arbitration cannot bind someone who has not author-
`ized the arbitrator to make that determination. As the
`
`Court explains, “[a]n arbitrator may employ class proce-
`dures only if the parties have authorized them.” Ante,
`at 1.
`
`The distribution of opt-out notices does not cure this
`fundamental flaw in the class arbitration proceeding in
`
`this case. “[A]rbitration is simply a matter of contract
` between the parties,” First Options of Chicago, Inc. v.
`
`Kaplan, 514 U. S. 938, 943 (1995), and an offeree’s silence
`does not normally modify the terms of a contract, 1 Re-
`statement (Second) of Contracts §69(1) (1979). Accord-
`ingly, at least where absent class members have not been
`required to opt in, it is difficult to see how an arbitrator’s
`decision to conduct class proceedings could bind absent
`class members who have not authorized the arbitrator to
`decide on a classwide basis which arbitration procedures
`are to be used.
`
`Class arbitrations that are vulnerable to collateral at-
`tack allow absent class members to unfairly claim the
`“benefit from a favorable judgment without subjecting
`themselves to the binding effect of an unfavorable one,”
`
`American Pipe & Constr. Co. v. Utah, 414 U. S. 538, 546–
`
`547 (1974).
`In the absence of concessions like Oxford’s,
`this possibility should give courts pause before concluding
`
`
`
`
`
`
`
`
`
`2
`
`
`

`
`
`
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`
` Cite as: 569 U. S. ____ (2013)
`
` ALITO, J., concurring
`
`
`that the availability of class arbitration is a question the
`arbitrator should decide. But because that argument was
`not available to petitioner in light of its concession below,
`I join the opinion of the Court.
`
`3