Supreme Court Rejects Government's Bid to Enforce Appeal Waivers in Federal Criminal Cases

The Supreme Court, in *Hunter v. United States*, 608 U.S. ___ (2026), established a significant "miscarriage of justice" exception to the enforceability of appeal waivers in federal criminal plea bargains. Decided by an 8-1 vote on June 18, 2026, the Court held that such waivers are unenforceable when their enforcement would perpetuate an egregious and obvious error that would bring the judicial system into disrepute. This decision creates a crucial safety valve for extreme cases, rejecting both the government's argument for absolute enforceability and narrower circuit interpretations. Legal professionals must now navigate this high bar, which is poised to reshape plea negotiations and appellate strategy, potentially signaling a seismic shift in criminal law akin to *Apprendi v. New Jersey*.

The landscape of federal criminal justice has been significantly altered by the Supreme Court's recent decision in *Hunter v. United States*, 608 U.S. ___ (2026), handed down on June 18, 2026. This landmark ruling introduces a "miscarriage of justice" exception to the appeal waivers that have become a standard feature of federal criminal plea agreements. While the 8-1 vote might suggest broad consensus, the underlying divisions and the expansive implications of the decision, particularly highlighted by Justice Gorsuch's concurrence, suggest that *Hunter* could be one of the most impactful criminal cases of the term.

At its core, *Hunter* addresses the tension between the finality sought by plea bargains and the judiciary's fundamental responsibility to correct egregious errors. By carving out this exception, the Supreme Court has provided a critical safety valve, ensuring that appellate courts retain the power to review sentences marred by errors so profound they would undermine public confidence in the justice system. This development is already drawing comparisons to *Apprendi v. New Jersey*, 530 U.S. 466 (2000), a decision that, initially under-recognized, ultimately revolutionized sentencing law and continues to have far-reaching effects.

For practicing attorneys, *Hunter* necessitates a re-evaluation of established practices in plea negotiations, the drafting of plea agreements, and appellate advocacy. It signals a potential shift in the balance of power within the plea bargaining system, offering defendants a narrow but vital avenue for recourse in circumstances previously thought to be foreclosed by waiver. Understanding the contours of this new exception and its practical implications will be paramount for navigating the evolving federal criminal justice system.

Plea bargaining is the bedrock of the federal criminal justice system, accounting for approximately 97% of all federal criminal convictions. A ubiquitous component of these agreements is the appeal waiver, wherein a defendant agrees to forgo their right to appeal their conviction or sentence in exchange for concessions from the government. These waivers are generally considered valid and enforceable if entered into knowingly and voluntarily, as required by Federal Rule of Criminal Procedure 11. Rule 11 mandates that a court personally address the defendant to ensure they understand the rights being waived and the consequences of their plea.

Despite the widespread use and general enforceability of appeal waivers, a significant circuit split had emerged regarding the circumstances under which such waivers might be set aside. Some circuits, like the Fifth Circuit in *Hunter*'s case, adopted a very narrow approach, typically recognizing exceptions only when the sentence exceeded the statutory maximum or the waiver itself was a product of ineffective assistance of counsel. Other circuits, however, had adopted a broader "miscarriage of justice" exception, allowing for appellate review in cases of egregious error. This divergence created inconsistencies in the application of justice across federal jurisdictions, setting the stage for the Supreme Court's intervention in *Hunter v. United States*.

The Supreme Court's decision in *Hunter v. United States* directly addressed this circuit split, ultimately endorsing the broader "miscarriage of justice" exception. The case originated from Munson Hunter III, who pleaded guilty to wire fraud and, as part of his plea agreement, signed an appeal waiver. At sentencing, the district court imposed a condition of supervised release requiring Hunter to take all prescribed mental health medications, a condition he objected to. The Fifth Circuit, adhering to its narrow precedent, dismissed Hunter's appeal, holding that the waiver precluded review even of a potentially unconstitutional sentence, so long as it did not exceed the statutory maximum or result from ineffective assistance of counsel.

Writing for the 8-1 majority, Justice Kagan held that an agreement not to appeal a sentence is unenforceable when its enforcement would result in a "miscarriage of justice." The Court defined "miscarriage of justice" as occurring "when it would leave in place the kind of egregious error that would bring the judicial system into disrepute." This standard sets a high bar, emphasizing that the error must be "obvious—not one a judge could reasonably make—and must be of the type that would undermine public confidence in the judiciary." The Court explicitly clarified that "standard-fare errors in misapplying sentencing law cannot cancel an appeal waiver," reserving this exception for truly extreme cases.

Examples provided by the Court to illustrate this high bar include a judge imposing a sentence beyond the statutory maximum, unconstitutionally considering factors like race or religion in sentencing, or imposing a sentence without "some minimum of civilized procedure," such as "let[ting] an orangutan pick a sentence out of a hat." The Court rejected both the government's argument for absolute enforceability of knowing and voluntary waivers and the Fifth Circuit's restrictive two-exception rule, instead adopting the majority view among appellate courts.

The 8-1 decision, with Justice Thomas dissenting, masks deeper jurisprudential tensions. Justice Gorsuch's concurrence, joined by Justices Sotomayor and Jackson, suggests a more fundamental skepticism about the pervasive role of plea bargaining in the criminal justice system. This echoes the initial reception of *Apprendi v. New Jersey*, 530 U.S. 466 (2000), which, by requiring any fact increasing a sentence beyond the statutory maximum (other than a prior conviction) to be found by a jury beyond a reasonable doubt, fundamentally reshaped sentencing practices. Like *Apprendi*, *Hunter* may portend similar seismic shifts, not just in appellate review but potentially in how plea agreements are structured and negotiated, as courts grapple with defining the precise boundaries of this "miscarriage of justice" exception.

The *Hunter v. United States* decision marks a pivotal moment for federal criminal practice, introducing a critical, albeit high-bar, exception to the enforceability of appeal waivers. For defense attorneys, this ruling provides a narrow but vital avenue to challenge truly egregious sentencing errors that would otherwise be insulated from review. It underscores the importance of meticulously documenting objections during sentencing, particularly concerning constitutional rights, and carefully evaluating the terms of appeal waivers during plea negotiations. While the bar is high, the "miscarriage of justice" exception means that a knowing and voluntary waiver is no longer an absolute shield against appellate scrutiny in all circumstances.

Prosecutors, conversely, must now consider the potential for this exception when drafting plea agreements, though the Court's emphasis on the rarity of such egregious errors suggests that the vast majority of waivers will remain enforceable. All practitioners should closely monitor how lower federal courts interpret and apply this new standard, particularly as the Fifth Circuit reconsiders Munson Hunter III's case under the Supreme Court's guidance. The full ramifications of *Hunter* will unfold over time, but it undeniably reinforces the judiciary's ultimate responsibility to uphold the integrity and public confidence in the justice system, even in the face of contractual agreements.