Hunter v. United States

(Slip Opinion) OCTOBER TERM, 2025 1 Syllabus NOTE: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued. The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader. See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. SUPREME COURT OF THE UNITED STATES Syllabus HUNTER v. UNITED STATES CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE FIFTH CIRCUIT No. 24–1063. Argued March 3, 2026—Decided June 18, 2026 Petitioner Munson Hunter III was charged with 10 counts of bank and wire fraud for a years-long scheme costing various financial institu- tions about half a million dollars. He entered into a written plea agree- ment with the Government under which he pleaded guilty to one count of aiding and abetting wire fraud in exchange for dismissal of the re- maining nine charges and a promise not to prosecute him for the de- scribed conduct in the future. The agreement included an appeal waiver under which Hunter waived the right to appeal his conviction and sentence, except that he did not waive the right to raise a claim of ineffective assistance of counsel. The agreement further provided that “any modification” of its terms “must be in writing and signed by all parties.” The District Court accepted the plea after deeming it know- ing and voluntary. At sentencing, the Probation Office recommended that as a condition of supervised release Hunter be required to participate in a mental- health treatment program and take all mental-health medications pre- scribed by his treating physician. Hunter objected to the mandatory- medication part of that condition. The District Court told Hunter that if “the treatment provider prescribes drugs, you should take them,” while also telling Hunter that he could “address” any future dispute about medication “to the probation officer” or, if needed, “to me.” The District Court then imposed a sentence of 51 months in prison followed by three years of supervised release, including the contested medica- tion condition. At the close of the hearing, the court told Hunter: “All right. You have a right to appeal. If you wish to appeal, [your trial counsel] will continue to represent you.” When asked if either party wished to say anything else, Hunter’s lawyer said “Nothing from the defense,” and the prosecutor replied: “Your Honor, I believe—well, no. 2 HUNTER v. UNITED STATES Syllabus I—no.” Hunter appealed, challenging the mandatory-medication condition as infringing on his “fundamental due process liberty interest in being free of unwanted mental health medication.” The Government sought dismissal based on the appeal waiver. Hunter acknowledged he had knowingly and voluntarily signed the waiver but argued that an ap- peal waiver is unenforceable when the disputed aspect of a sentence violates a fundamental constitutional right, and alternatively that the District Court’s statement at sentencing about appeal rights, along with the prosecutor’s failure to object, voided the waiver. The Court of Appeals for the Fifth Circuit dismissed the appeal, holding that the District Court’s misstatement “did not impact the validity of the appeal waiver” and that under Circuit precedent the “general rule” that ap- peal waivers are enforceable has only two exceptions: when the waiver was tainted by ineffective assistance of counsel and when the sentence exceeded the statutory maximum. Because neither exception applied, the Fifth Circuit held that Hunter’s appeal could not go forward. Held: An agreement not to appeal a sentence is unenforceable when it would result in a miscarriage of justice—meaning, when it would leave in place the kind of egregious error that would bring the judicial sys- tem into disrepute. Pp. 5–14. (a) The District Court’s misstatement at sentencing and the Govern- ment’s silence did not negate Hunter’s knowing and voluntary appeal waiver. The plea agreement specified that “[a]ny modification” of its terms “must be in writing and signed by all parties,” and even assum- ing away that provision, nothing that happened in the sentencing hearing shows the mutual agreement between parties needed to ac- complish a modification. The court’s statement about appeal rights could not change the parties’ agreement because it is the parties’ intent that matters, and their non-response falls far short of showing agree- ment to alter a conflicting term. The Government did not waive or forfeit its right to enforce the ap- peal waiver by failing to correct the court’s misstatement. Under ordi- nary litigation principles, waiver requires some affirmative signal of abandonment, and staying silent—as here, not picking a fight—does not qualify. Forfeiture generally does happen through silence because it is the failure to make the timely assertion of a right, but the proper time for the Government to assert its right to enforce an appeal waiver is after a defendant files a notice of appeal, not at sentencing. The decision that Hunter’s appeal waiver remains valid matches one the Court reached in a nearly mirror-image case, Class v. United States, 583 U. S. 174. Pp. 5–7. (b) The question becomes whether the Government’s right to enforce an appeal waiver has limits and, if so, what they are. It is common  Cite as: 608 U. S. ___ (2026) 3 Syllabus ground that an appeal waiver must be knowing and voluntary to be valid and thus to be enforceable, and that an appeal waiver is not knowing and voluntary if it was the product of ineffective assistance of counsel. Putting that to the side, the Fifth Circuit holds appeal waiv- ers unenforceable only when the sentence exceeds the statutory maxi- mum. The Government maintains that knowing and voluntary appeal waivers are always enforceable. But most courts of appeals have in- stead taken a less stringent approach, declining to enforce appeal waivers when doing so would produce a “miscarriage of justice.” The question for the Court is which position is right. The answer stems from the special, and indeed pivotal, role of the judiciary in approving and implementing appeal waivers. A district court must accept the plea agreement, including any appeal waiver, before it can go into effect, and that decision is one given over to “sound judicial discretion.” Santobello v. New York, 404 U. S. 257, 261–262. An appeal waiver then falls into the lap of a court of appeals, which has exclusive control over its operation; the real-world effect of a waiver turns only on whether the appeals court decides to enforce it, and enforcement will cement into place a district court’s sentence whether or not lawful. Because that is so, the standard for enforcing appeal waivers implicates the interests not only of the plea agree- ment’s parties, but also of the judiciary. If a court always enforces appeal waivers regardless of the kind or degree of error tainting a sen- tence, the judicial system’s integrity may come into question. The Court has recognized when addressing waivers of other rights held by criminal defendants that federal courts have an “independent” “insti- tutional interest” in ensuring that legal proceedings “appear fair to all who observe them,” Wheat v. United States, 486 U. S. 153, 160, and that some rules may be “so fundamental” that they could not be waived “without irreparably discrediting the federal courts,” United States v. Mezzanatto, 513 U. S. 196, 204. Whatever the parties have agreed to, the court’s own responsibility when enforcing a waiver is apparent, and so automatic enforcement may “risk[ ] institutional harm.” Id., at 205. Accordingly, neither the Government’s nor the Fifth Circuit’s pro- posed rule can be the right one. The Government’s position first runs into the scenario that even the Fifth Circuit will not tolerate: when a judge imposes a sentence beyond what the relevant statute allows. Suppose a judge sentences a misdemeanant to life in prison, when the applicable law caps a prison term at one year; if an appellate court had to dismiss the resulting appeal, it would call into doubt the judicial system’s very attachment to law. But so too would a dismissal in cer- tain other situations, which fall outside both the Government’s and the Fifth Circuit’s rules—for example, if the sentencing judge 4 HUNTER v. UNITED STATES Syllabus unconstitutionally considered race or religion, imposed a condition that a defendant not become pregnant, or “let an orangutan pick a sen- tence out of a hat.” Tr. of Oral Arg. 66. However certain the parties’ agreement, the courts are too enmeshed in its approval and implemen- tation to escape responsibility for such results. Pp. 7–11. (c) The Court thus approves the majority view among the courts of appeals that an appeal waiver is unenforceable when it would result in a miscarriage of justice. The miscarriage-of-justice standard sets a high bar. The waiver may be set aside only if the sentence is marred by the kind of egregious error that would bring the judicial system into disrepute. The error must be obvious—not one a judge could reasona- bly make—and must be of the type that would undermine public con- fidence in the judiciary. Standard-fare errors in misapplying sentenc- ing law cannot cancel an appeal waiver. But a high bar is not the same as an insurmountable one; the miscarriage-of-justice limit, as many appellate courts have properly applied it, offers a safety valve for ex- treme cases when the justice system’s basic integrity is at stake. The nature of the miscarriage-of-justice limit precludes any attempt to list all the situations in which it will overcome an appeal waiver. But a few examples of the kinds of errors that would bring the judiciary into disrepute may provide guidance to lower courts: a sentence ex- ceeding what the relevant statute allows; a sentence infected with a blatant constitutional error, such as when a judge takes account of a constitutionally impermissible factor (like race) or imposes a constitu- tionally infirm condition of supervised release; and a sentence imposed without some minimum of civilized procedure. These examples are just examples, not intended to be exclusive, but they serve to illustrate the high bar a defendant must surmount to overcome an appeal waiver. The Court doubts that this confined exception will “open the flood- gates” to “waived appeals.” Tr. of Oral Arg. 60, 87. Many Circuits already apply a miscarriage-of-justice limit, and the Government has offered no evidence those courts are awash with appeals. The Circuits using this approach have understood it to erect a substantial barrier, and such a hard-to-meet standard presumably deters many appeals while those still filed can often be quickly dismissed because the errors asserted are uncertain or ordinary. Pp. 11–13. (d) The Court declines to decide in the first instance whether Hunter’s challenge to the mandatory-medication condition satisfies the miscarriage-of-justice standard. The Court of Appeals did not ad- dress the question, and this Court is “a court of review, not of first view,” Cutter v. Wilkinson, 544 U. S. 709, 718, n. 7. It is therefore up to the Fifth Circuit to decide whether enforcing Hunter’s appeal waiver would result in a miscarriage of justice. Pp. 13–14.  Cite as: 608 U. S. ___ (2026) 5 Syllabus Vacated and remanded. KAGAN, J., delivered the opinion of the Court, in which ROBERTS, C. J., and ALITO, SOTOMAYOR, GORSUCH, KAVANAUGH, BARRETT, and JACKSON, JJ., joined. GORSUCH, J., filed a concurring opinion, in which SOTOMAYOR and JACKSON, JJ., joined. KAVANAUGH, J., filed a concurring opinion, in which ALITO and BARRETT, JJ., joined. BARRETT, J., filed a concurring opinion. THOMAS, J., filed a dissenting opinion.  Cite as: 608 U. S. ____ (2026) 1 Opinion of the Court NOTICE: This opinion is subject to formal revision before publication in the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, pio@supremecourt.gov, of any typographical or other formal errors. SUPREME COURT OF THE UNITED STATES _________________ No. 24–1063 _________________ MUNSON P. HUNTER, III, PETITIONER v. UNITED STATES ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE FIFTH CIRCUIT [June 18, 2026] JUSTICE KAGAN delivered the opinion of the Court. Plea agreements between a criminal defendant and the Government often include an appeal waiver—a promise by the defendant not to appeal his conviction or eventual sen- tence. In this case, we address a dispute about when such a promise is unenforceable in the sentencing context. We principally hold that an agreement not to appeal a sentence is unenforceable when it would result in a miscarriage of justice—meaning, when it would leave in place the kind of egregious error that would bring the judicial system into disrepute. I Petitioner Munson Hunter III entered into a written plea agreement with the Government after he was charged with ten counts of bank and wire fraud for a years-long scheme costing various financial institutions about half a million dollars. Under the agreement, Hunter pleaded guilty to one count of aiding and abetting wire fraud. In exchange, the Government agreed to dismiss the other nine charges and to refrain from prosecuting Hunter in the future for the con- duct they described. 2 HUNTER v. UNITED STATES Opinion of the Court The agreement also included an appeal waiver, applying to both Hunter’s conviction and his still-to-be-decided sen- tence. Under that provision, Hunter “knowingly and volun- tarily waive[d] the right to appeal” his conviction and sen- tence, except that he did “not waive the right to raise a claim of ineffective assistance of counsel.” App. to Pet. for Cert. 6a. And with specific reference to his sentence, Hunter acknowledged his “aware[ness]” of certain facts: that the sentence had “not yet been determined” by the Dis- trict Court; that the Government had made no “promise or representation” about that sentence; and that the “sentence to be imposed [was] within the sole discretion of the sen- tencing judge.” Id., at 7a, 8a, 10a. The plea agreement fur- ther specified what would happen if Hunter nonetheless ap- pealed: The Government would “assert its rights under this agreement and seek specific performance” of Hunter’s ap- peal waiver. Id., at 7a. Finally, the agreement provided that “[a]ny modification” of its terms—including of the ap- peal waiver—“must be in writing and signed by all parties.” Id., at 15a. After the agreement was reached, the District Court held a hearing to decide whether to accept Hunter’s plea. To en- sure that Hunter fully grasped the consequences of the agreement, the court went over each of its terms. Upon reaching the appeal waiver, the court read it aloud, ex- plained what it meant—among other things, that “[b]asi- cally you’re agreeing to whatever sentence I impose”—and asked Hunter whether he understood. App. 11. When Hunter replied “Yes” to that and similar questions, the court deemed the plea “knowing and voluntary,” adjudged Hunter guilty of aiding and abetting wire fraud, and sched- uled a sentencing hearing. Id., at 11, 14–15; see id., at 11– 15. At that hearing, much of the discussion focused on a con- dition of supervised release that the Probation Office rec- ommended go into effect once Hunter completed his prison  Cite as: 608 U. S. ____ (2026) 3 Opinion of the Court sentence. According to the Office’s presentence report, Hunter “suffers from symptoms of anxiety and depression” and “has refused medication to treat his symptoms.” Presentence Report in No. 23–cr–85 (SD Tex.), ECF Doc. 125, p. 19. The report thus proposed that, while on supervised release, Hunter be required to “participate in a mental- health treatment program” and to “take all mental-health medications that are prescribed by [his] treating physi- cian.” Id., at 24. Hunter objected to the mandatory-medi- cation part of that condition, saying that he should not “be forced to medicate.” App. to Pet. for Cert. 24a. The judge responded that if “the treatment provider prescribes drugs, you should take them,” while also telling Hunter that he could “address” any future dispute about medication “to the probation officer” or, if needed, “to me.” Ibid. The District Court later imposed its sentence and made closing remarks, including a fairly inexplicable one at issue here. Under the sentence, Hunter would have to serve 51 months in prison, followed by three years of supervised re- lease. The release conditions would include the medication requirement to which Hunter had objected. After specify- ing those terms, the court granted the Government’s motion to dismiss the remaining counts in the indictment, con- firmed with Hunter’s lawyer that the Government had com- plied with the plea agreement, and finally addressed Hunter. The court said: “All right. You have a right to ap- peal. If you wish to appeal, [your trial counsel] will con- tinue to represent you.” Id., at 36a. Then turning back to the lawyers, the court asked whether either “wish[ed] to say anything else.” Ibid. Hunter’s lawyer answered: “Nothing from the defense.” The prosecutor replied: “Your Honor, I believe—well, no. I—no.” Ibid. And the hearing adjourned. Hunter promptly appealed, challenging the mandatory- medication condition. That condition, he argued, “in- fringe[d] on [his] fundamental due process liberty interest in being free of unwanted mental health medication.” Brief 4 HUNTER v. UNITED STATES Opinion of the Court for Appellant in No. 24–20211 (CA5), p. 9. The Government sought dismissal, citing the appeal waiver in Hunter’s plea agreement. Hunter acknowledged that he had knowingly and voluntarily signed on to that provision, but urged two reasons for still permitting the appeal to proceed. Most broadly, he contended that an appeal waiver is unenforcea- ble when the disputed aspect of a sentence “violates a fun- damental constitutional right.” Ibid. In the alternative, he asserted that the District Court’s representation at sen- tencing that he had a right to appeal, along with the prose- cutor’s failure to object, voided the appeal waiver he had made. See id., at 8–9. The Court of Appeals for the Fifth Circuit dismissed Hunter’s appeal based on the waiver provision. The court first concluded that the District Court’s misstatement at sentencing “did not impact the validity of the appeal waiver.” 2024 WL 5003582, *1 (Dec. 6, 2024) (per curiam). And such a waiver, the court next held, controls even if the District Court imposed an “unconstitutional sentence.” Ibid. (citing United States v. Barnes, 953 F. 3d 383, 389 (CA5 2020)). Under Circuit precedent, the “general rule” that appeal waivers are enforceable has “only two excep- tions”: when the waiver itself was “tainted by ineffective as- sistance of counsel” and when the challenged sentence “ex- ceed[ed] the statutory maximum.” Id., at 388–389; United States v. White, 307 F. 3d 336, 339 (CA5 2002). Because neither exception applied, Hunter’s appeal could not go for- ward. We granted certiorari, 607 U. S. 961 (2025), because the Courts of Appeals have differed on when appeal waivers are unenforceable in the sentencing context. Most have held that a waiver cannot be enforced if doing so would result in a miscarriage of justice.1 The Fifth Circuit and a few others —————— 1 See United States v. Boudreau, 58 F. 4th 26, 33 (CA1 2023); United States v. Khattak, 273 F. 3d 557, 562 (CA3 2001); United States v. Smith,  Cite as: 608 U. S. ____ (2026) 5 Opinion of the Court have declined that route, instead specifying just a few dis- crete circumstances in which an appeal can occur despite a waiver.2 Today, we adopt the “miscarriage of justice” ap- proach, and accordingly remand this case to the Fifth Cir- cuit to consider whether, under that standard, Hunter’s ap- peal should still be dismissed. II Before getting to that issue, though, we pause to address the more case-specific argument Hunter makes for allowing him to appeal: that at his sentencing hearing, the District Court said he could, and the Government did not object. If that alone were enough to negate a knowing and voluntary appeal waiver, Hunter could bring his appeal regardless of our resolution of the just-described Circuit split. But it is not enough: Contrary to Hunter’s arguments, the court’s re- mark did not modify the plea agreement, nor did the Gov- ernment’s failure to object give up its ability to later enforce the agreement’s terms. First, the court’s statement about appeal rights could not have “orally modified the plea agreement” between Hunter and the Government. Brief for Hunter 12. That agreement, as earlier noted, was specific about how modifications could occur: only if “in writing and signed by all parties.” App. to Pet. for Cert. 15a; see supra, at 2. And even assuming away that provision, nothing that happened in the sentencing hearing shows the mutual agreement between parties —————— 134 F. 4th 248, 261 (CA4 2025); United States v. Andis, 333 F. 3d 886, 891–892 (CA8 2003); United States v. Wells, 29 F. 4th 580, 583 (CA9 2022); United States v. Holzer, 32 F. 4th 875, 886 (CA10 2022); United States v. Guillen, 561 F. 3d 527, 531–532 (CADC 2009); see also United States v. Riggi, 649 F. 3d 143, 148 (CA2 2011) (adopting a differently framed but substantively similar exception). 2 See United States v. Barnes, 953 F. 3d 383, 388–389 (CA5 2020); Por- tis v. United States, 33 F. 4th 331, 339 (CA6 2022); United States v. Nulf, 978 F. 3d 504, 507 (CA7 2020); King v. United States, 41 F. 4th 1363, 1368, n. 3 (CA11 2022). 6 HUNTER v. UNITED STATES Opinion of the Court needed to accomplish a modification. See Hawkins v. United States, 96 U. S. 689, 696 (1877) (“Mutual consent is required to modify” an agreement). There was neither an offer nor an acceptance by those parties, and so no conceiv- able meeting of the minds. It seems unlikely that, as Hunter urges, the court’s statement was meant to produce a modification, see Brief for Hunter 42; far more likely, given that the court did not refer to the parties’ bargain, that its statement was merely a momentary mistake. But whatever the court’s intent, its statement about appeal rights could not change Hunter and the Government’s agreement. For that purpose, it is the parties’ intent that matters, and their non-response response to the judge’s rep- resentation falls far short of showing that they agreed to alter a conflicting term. Second, the Government did not forever “relinquish[ ] its appeal-waiver argument” by failing to correct the court’s misstatement. Id., at 12. The prosecutor’s swallowed retort at the hearing (“Your Honor, I believe—well, no. I—no”) neither waived nor forfeited, as Hunter claims, the right to seek future enforcement of Hunter’s agreement not to ap- peal. See ibid. Under ordinary litigation principles, a waiver of a right requires some affirmative signal of “aban- donment.” United States v. Olano, 507 U. S. 725, 733 (1993). Staying silent—as here, not picking a fight—does not qualify. By contrast, forfeiture generally does happen through silence, because it “is the failure to make the timely assertion of a right.” Ibid. But the proper time for the Gov- ernment to assert its right to enforce an appeal waiver is not at a sentencing hearing. Rather, it is after a defendant has filed a notice of appeal. It is only then that the Govern- ment can assess whether the appeal violates the agree- ment’s terms and, even if so, whether to turn a blind eye. See Garza v. Idaho, 586 U. S. 232, 238–239 (2019). So here, the Government’s nonobjection during the sentencing pro- ceeding was not a “failure to make the timely assertion” of  Cite as: 608 U. S. ____ (2026) 7 Opinion of the Court its enforcement right. Olano, 507 U. S., at 733 (emphasis added). That assertion—or its absence—would happen only later on. Our decision that Hunter’s appeal waiver remains valid matches one we reached in a nearly mirror-image case. In Class v. United States, 583 U. S. 174 (2018), the defendant’s plea agreement did not include an appeal waiver, but dur- ing the plea colloquy the District Court mistakenly stated that the defendant was “giving up [his] right to appeal [his] conviction.” Id., at 185 (alterations in original). The de- fendant agreed to the court’s representation. When he later filed a notice of appeal, the Government argued that he had relinquished his appeal right in that courtroom exchange. We rejected that view, holding that the defendant’s “acqui- escence neither expressly nor implicitly waived his right to appeal.” Ibid. Similarly in this case, any acquiescence that the Government’s silence conveyed “neither expressly nor implicitly” gave up its right under the plea agreement. It is just that here the relevant right is not to appeal, but instead to enforce the appeal waiver. III The question then becomes whether that right to enforce has limits (beyond any stated in the agreement itself ) and, if so, what they are. It is common ground that an appeal waiver, like the rest of a plea agreement, must be knowing and voluntary to be valid and thus to be enforceable. See Brady v. United States, 397 U. S. 742, 748 (1970).3 Related to that settled rule is another: An appeal waiver, again like the rest of the agreement, is not knowing and voluntary if it was the product of ineffective assistance of counsel. See Hill v. Lockhart, 474 U. S. 52, 56 (1985) (“[T]he —————— 3 We do not otherwise address in this opinion the circumstances in which an appeal waiver might be invalidly obtained, as through fraud or coercion. We instead discuss only when a validly obtained waiver may become unenforceable. 8 HUNTER v. UNITED STATES Opinion of the Court voluntariness of [a] plea depends on whether counsel’s ad- vice was within the range of competence demanded of attor- neys in criminal cases”). So an appeal waiver tainted by ineffective assistance is not enforceable.4 Putting that to the side, the Fifth Circuit, as noted above, holds appeal waivers unenforceable in only one circumstance: when the sentence sought to be appealed exceeds the statutory max- imum. See supra, at 4. The Government here espouses yet a stricter view, maintaining that knowing and voluntary appeal waivers are always enforceable. See Brief for United States 10, 12, 30–31; Tr. of Oral Arg. 63–64. But as Hunter notes, most courts of appeals have instead taken a less stringent approach, declining to enforce appeal waivers when doing so would produce a “miscarriage of justice.” See Brief for Hunter 34–37; supra, at 4–5, and n. 1. Which po- sition is right? The answer stems from the special, and indeed pivotal, role of the judiciary in approving and implementing appeal waivers. Such a provision, of course, is part of the bargain struck by a defendant and prosecutor, without judicial in- volvement. See Fed. Rule Crim. Proc. 11(c)(1). But the dis- trict court must accept the plea agreement, including any appeal waiver, before it can go into effect. See Rule 11(c)(3)(A) (“[T]he court may accept the agreement, reject it, or defer a decision”). And that decision is one given over —————— 4 Every Circuit, including the Fifth, has recognized as much. See United States v. Ortiz-Vega, 860 F. 3d 20, 28 (CA1 2017); United States v. Lloyd, 901 F. 3d 111, 124 (CA2 2018); United States v. Fazio, 795 F. 3d 421, 426 (CA3 2015); Smith, 134 F. 4th, at 261; Barnes, 953 F. 3d, at 388– 389; United States v. Toth, 668 F. 3d 374, 377–378 (CA6 2012); Nulf, 978 F. 3d, at 506–507; Andis, 333 F. 3d, at 890–891; United States v. Silveira, 997 F. 3d 911, 913 (CA9 2021); Holzer, 32 F. 4th, at 886; United States v. Puentes-Hurtado, 794 F. 3d 1278, 1284 (CA11 2015); Guillen, 561 F. 3d, at 530–531. And in any event, the Government appears to include an ineffective-assistance exception in all plea agreements it makes, as it did in Hunter’s. See U. S. Dept. of Justice, Manual §9–16.330 (Jan. 2020); supra, at 2.  Cite as: 608 U. S. ____ (2026) 9 Opinion of the Court to “sound judicial discretion.” Santobello v. New York, 404 U. S. 257, 262 (1971); see Advisory Committee’s Notes on 1974 Amendment to Fed. Rule Crim. Proc. 11, 18 U. S. C. App., p. 53 (“[T]he acceptance or rejection of a plea agree- ment” is “left to the discretion of the individual trial judge”). If thus approved, an appeal waiver next falls into the lap of a court of appeals, which has exclusive control over its op- eration. Nothing, after all, literally prevents a defendant who has signed such a waiver from filing an appeal: The court’s docket is as open to him as to any other unhappy litigant. So the real-world effect of a waiver provision turns, and turns only, on whether the appeals court decides to enforce it. And the consequence of that decision has eve- rything to do with courts and the judgments they render. If enforced, the appeal waiver will, by eliminating judicial re- view, cement into place a district court’s sentence, whether or not lawful. From start to finish, then, courts are in the middle of, and partly responsible for, appeal waivers and their results. Because that is so, the standard for enforcing appeal waivers implicates the interests not only of the agreement’s parties, but also of the judiciary. If a court always carries out those waivers—no matter the kind or degree of error tainting a sentence—the judicial system’s integrity may come into question. This Court has explained the point when addressing waivers of other rights held by criminal defendants. In Wheat v. United States, 486 U. S. 153 (1988), for example, we held that a defendant’s waiver of a lawyer’s conflict of interest did not necessarily “cure[ ] [the] problem[ ]” because he was not the only one with a stake: The “[f]ederal courts,” we reasoned, have an “independent” “institutional interest” in ensuring that legal proceedings “appear fair to all who observe them.” Id., at 160. So too, in United States v. Mezzanatto, 513 U. S. 196 (1995), we rec- ognized that some evidentiary rules may be “so fundamen- tal” to a trial’s legitimacy that they could not be waived 10 HUNTER v. UNITED STATES Opinion of the Court “without irreparably discrediting the federal courts.” Id., at 204 (alteration omitted). To show the idea’s obviousness, we borrowed from a court of appeals’ opinion: “[I]f the par- ties stipulated to trial by 12 orangutans[,] the defendant’s conviction would be invalid notwithstanding his consent, because some minimum of civilized procedure is required by community feeling regardless of what the defendant wants.” Ibid. (quoting United States v. Josefik, 753 F. 2d 585, 588 (CA7 1985) (Posner, J.)). But more prosaic exam- ples are not hard to come by: “We have repeatedly stressed the importance” of “the interest of the Judiciary and the public in correcting grossly prejudicial errors of law that undermine confidence in our legal system.” Greenlaw v. United States, 554 U. S. 237, 262 (2008) (ALITO, J., dissent- ing) (citing cases). And that interest, for the reasons just given, may be in play when a court is called on to enforce an appeal waiver. Whatever the parties have agreed to, the court’s own responsibility is apparent, and so automatic en- forcement may “risk[ ] institutional harm.” Mezzanatto, 513 U. S., at 205. For that reason, neither the Government’s nor the Fifth Circuit’s proposed rule can be the right one. The Govern- ment’s maximalist position first runs into the scenario that even the Fifth Circuit will not tolerate: when a judge im- poses on a defendant who has signed an appeal waiver a sentence beyond what the relevant statute allows. See United States v. Kim, 988 F. 3d 803, 810, n. 1 (CA5 2021) (declining to enforce an appeal waiver in such a case be- cause of “the legal truism that a court must not impose a sentence” that is “unauthorized by law”). Suppose, for ex- ample, that a judge sentences a misdemeanant to life in prison, when the applicable law caps a prison term at one year. If an appellate court had to dismiss the resulting ap- peal, it would call into doubt the judicial system’s very at- tachment to law. But so too would a dismissal in certain other situations, which fall outside both the Government’s  Cite as: 608 U. S. ____ (2026) 11 Opinion of the Court and the Fifth Circuit’s rules. Consider some examples of- fered at oral argument in this case. If, say, the sentencing judge was biased against individuals of one race or religion, and unconstitutionally considered that factor in imposing a sentence. See Tr. of Oral Arg. 64. Or if the judge (as in an actual case) imposed as a condition of supervised release that the defendant not become pregnant. See id., at 77; People v. Zaring, 8 Cal. App. 4th 362, 373–375 (1992). Or if the judge, to use a variation on Mezzanatto’s absurdity, “let an orangutan pick a sentence out of a hat.” Tr. of Oral Arg. 66; see supra, at 10. Those sentences would likewise impugn the judiciary’s integrity if an appeal waiver com- pelled them to stand. However certain the parties’ agree- ment, the courts are too enmeshed in its approval and im- plementation to escape responsibility for such results. We thus approve the majority view among the courts of appeals that an appeal waiver is unenforceable when it would result in a miscarriage of justice. That rule, properly understood and applied, sets a high bar: The waiver may be set aside only if the sentence is marred by the kind of egre- gious error that would bring the judicial system into disre- pute. The error must be obvious—not one a judge could rea- sonably make. And it must be of the type that would undermine public confidence in the judiciary. Sentencing is a complex affair in our criminal justice system, involving for example the detailed calculation of a Sentencing Guide- lines range and the mandatory consideration of multiple sentencing factors. In that endeavor, it is unfortunate but inevitable that mistakes will occur. Such standard-fare er- rors in misapplying sentencing law cannot cancel an appeal waiver. Were they to do so, the utility of waivers in plea negotiations could plummet: such a provision would have less value to the Government, and so might induce fewer concessions to a defendant. And still more to our point, that kind of standard error is not likely to discredit the judici- ary’s commitment to law. But some faults in sentencing 12 HUNTER v. UNITED STATES Opinion of the Court can. So a high bar is not the same as an insurmountable one. The point of the miscarriage-of-justice limit, as many appellate courts have properly applied it, is to offer a safety valve for extreme cases—a way out of a waiver when the justice system’s basic integrity is at stake. The nature of the miscarriage-of-justice limit precludes any attempt to list all the situations in which it will over- come an appeal waiver. Extreme cases, after all, are hard to anticipate before they happen. But a few examples of the kinds of errors we mean—the kind that would bring the ju- diciary into disrepute—may provide guidance to lower courts. First, a defendant may appeal a sentence exceeding what the relevant statute allows—most commonly, a term of years above the maximum prescribed. See, e.g., Kim, 988 F. 3d, at 810–811, and n. 1; supra, at 10. Second, a defend- ant may appeal a sentence that is infected with a blatant constitutional error, such as when a judge takes account of a constitutionally impermissible factor (like race) or im- poses a constitutionally infirm condition of supervised re- lease (like barring a defendant from becoming pregnant). See, e.g., United States v. Elliott, 264 F. 3d 1171, 1173 (CA10 2001); supra, at 11. And third, a defendant may ap- peal if his sentence was imposed without “some minimum of civilized procedure” as in, yes, the “twelve orangutans” case—or less extravagantly, one in which the judge refused to hold a hearing consonant with basic principles of law. United States v. Adkins, 743 F. 3d 176, 192–193 (CA7 2014); see United States v. Behrens, 375 U. S. 162, 165–166 (1963). These examples are just examples, not intended to be exclusive, but they serve to illustrate the high bar a de- fendant must surmount to overcome an appeal waiver. Contrary to the Government’s assertion, we doubt that such a confined exception to the rule of enforcement will “open the floodgates” to “waived appeals.” Tr. of Oral Arg. 60, 87; see id., at 62. As earlier noted, many Circuits al- ready place a miscarriage-of-justice limit on appeal  Cite as: 608 U. S. ____ (2026) 13 Opinion of the Court waivers. See supra, at 4–5, n. 1. The Government has of- fered no evidence that those courts are awash with appeals, much less ones demanding serious litigation. Nor is that dearth of support surprising. The Circuits using the mis- carriage-of-justice approach have mainly understood it to erect a substantial barrier, just as we require today. See, e.g., United States v. Santiago, 769 F. 3d 1, 8 (CA1 2014) (The “exception is meant only for egregious cases and is to be applied sparingly”); United States v. Andis, 333 F. 3d 886, 891 (CA8 2003) (The exception is “a narrow one” be- cause appeal waivers “should not be easily voided”). Such a hard-to-meet standard presumably deters many appeals. And those still filed can often be quickly dismissed because the errors asserted are uncertain or ordinary. Thankfully, the kinds of sentences that raise miscarriage-of-justice con- cerns, as we have described them, are rare in our justice system. The possibility of correction helps keep them so, and thus safeguards that system’s integrity, without impos- ing excessive burdens on either the appeals courts or the Government. Hunter and the Government here dispute whether, under the right legal standard, his appeal can go forward. Recall that Hunter wants to challenge the District Court’s require- ment that, while on supervised rel