The U.S. Courts of Appeals for the thirteen "circuits" issue thousands of precedential decisions each year. Because relatively few of these decisions are ultimately reviewed by the Supreme Court, the U.S. Courts of Appeals are often the last word on consequential legal questions. The federal appellate courts sometimes reach different conclusions on the same issue of federal law, causing a "split" among the circuits that leads to the nonuniform application of federal law among similarly situated litigants.

This Legal Sidebar discusses circuit splits that emerged or widened following decisions from August 2026 on matters relevant to Congress. The Sidebar does not address every circuit split that developed or widened during this period. Selected cases typically involve judicial disagreement over the interpretation or validity of federal statutes and regulations, or constitutional issues relevant to Congress's lawmaking and oversight functions. The Sidebar includes only cases where an appellate court's controlling opinion recognizes a split among the circuits on a key legal issue resolved in the opinion. This Sidebar refers to each U.S. Court of Appeals by its number or descriptor (e.g., "D.C. Circuit" for "U.S. Court of Appeals for the D.C. Circuit").

Some cases identified in this Sidebar, or the legal questions they address, are examined in other CRS general distribution products. Members of Congress and congressional staff may click here to subscribe to the CRS Legal Update and receive regular notifications of new products and upcoming seminars by CRS attorneys.

• Arbitration: The Seventh Circuit affirmed a lower court's denial of a defendant's motion to compel arbitration, holding that the district court did not commit clear error in denying the motion after the lower court found that the defendant's actions before class certification waived its right to compel arbitration. The panel decided that the Supreme Court's 2018 decision in U.S. Bank National Association v. Village at Lakeridge, LLC abrogated earlier circuit precedent that applied a de novo standard of review to all denials of motions to compel arbitration. The panel declared that post-Lakeridge, the standard of review that applies to lower court decisions on a mixed question of law and fact depends on whether the question involves primarily legal or factual issues. Those aspects of a lower court's decision that expound on the law and, if upheld, would have a precedential effect on future cases are reviewed de novo. However, mixed questions involving "case-specific factual considerations" are reviewed for clear error. In the panel's view, waiver decisions are mixed questions of law and fact and thus should be reviewed for clear error, except to the extent the decision announces a new legal rule. The panel observed that it split with the First, Second, Fourth, Fifth, Sixth, Eighth, Ninth, and Eleventh Circuits that, post-Lakeridge, have continued to uniformly apply the de novo standard to the review of denials of motions to compel arbitration, including when the basis for the denial was a party's waiver of a right to arbitrate (Moore v. Club Exploria, LLC).
• Civil Procedure: A divided Ninth Circuit panel upheld a district court's award of attorney's fees to the defendant in a false-advertising case brought under the Lanham Act. The Act allows awards of fees in "exceptional cases." The panel majority held that the district court did not abuse its discretion in deciding that standard was satisfied here because the plaintiffs pursued their suit against the defendant despite repeated dismissals of similar claims they had brought in other cases. The majority also held that the defendant could recover attorney's fees as part of "costs" under Federal Rule of Civil Procedure 41(d), which permits the recovery of "costs" accrued when a plaintiff who voluntarily dismissed an action in any court then files an action based on the same claim against the same defendant. The majority observed that circuit courts had taken varied approaches to assess the availability of attorney's fees under Rule 41(d). The majority described itself as aligning most closely with the Fourth and Fifth Circuits in holding that attorney's fees can be awarded under Rule 41(d) if the statute underlying the litigation provides for the award of attorney's fees, as was the case here. The majority acknowledged a split with published opinions by the Second and Eighth Circuits, which the majority described as holding that attorney's fees may be awarded under Rule 41(d) at the discretion of the court, and the Sixth Circuit, which holds that attorney's fees are never available under Rule 41(d) (ThermoLife Int'l, LLC v. BPI Sports, LLC).
• Civil Procedure: The Tenth Circuit held that it lacked jurisdiction to review a post-judgment contempt order directing the appellant to stop violating an earlier injunction or show cause as to why the violation occurred. Under 28 U.S.C. § 1291, circuit courts have appellate jurisdiction over "final" district court decisions. The Tenth Circuit reasoned that it lacked jurisdiction to review the contempt order under § 1291 because the lower court's order would not be final unless it made a contempt finding and imposed a sanction on a party. The panel observed that its interpretation of § 1291 conflicted with the approach taken by the Third Circuit in a few cases in which it exercised appellate jurisdiction over post-judgment enforcement orders in the absence of a contempt finding and sanction (Fischer v. XTO Energy).
• Civil Procedure: In a dispute over application of the federal officer removal statute, the Eleventh Circuit held that removal of a case from state to federal court was proper when a municipality brought suit against private parties for pollutants emanating from a Superfund site designated by the Environmental Protection Agency (EPA). Under 28 U.S.C. § 1442, a suit against a private party "acting under" a federal officer may be removed to federal court if it relates to the party's assistance in the performance of the officer's official duties. In this case, the federal district court had concluded that the defendant had not satisfied the criteria for removal, ordered remand of the suit to state court, and denied the defendant's request that the district court stay its remand order pending appeal. Following the district court's remand, state court litigation against the defendant proceeded while its appeal to the Eleventh Circuit was pending. The Eleventh Circuit reversed the lower court's decision, holding that removal to federal court was proper because the defendants' alleged liability arose from their obligations under an EPA-mandated consent decree to remediate the site, which the EPA would otherwise have had to remediate under the Comprehensive Environmental Response, Compensation, and Liability Act. Agreeing with the Fourth Circuit and splitting with the Ninth Circuit, the panel held that the Supreme Court's decision in Coinbase, Inc. v. Bielski, which mandates automatic stays for interlocutory appeals of arbitration denials, also applies in the federal officer removal context. Here, the panel held that Coinbase required an automatic stay of all district court proceedings, including its remand order, pending resolution of the appeal, irrespective of the subsequent state proceedings, and the lower court erred in refusing to stay its decision while that appeal was pending. The panel therefore reversed the district court's remand of the case to state court (City of Brunswick v. Honeywell Int'l, Inc.).
• Civil Procedure: A divided Ninth Circuit panel held that a federal district court erred when it blocked the Federal Trade Commission (FTC) from collecting on a money judgment against the operator of an alleged telemarketing scheme and his wife under the Federal Debt Collection Procedure Act (FDCPA). Both federal and state laws address debt collection, and while states typically provide statutes of limitations for the collection of debts in their jurisdictions, the FDCPA provides no statute of limitations for the enforcement of "debts" against the United States. Here, the lower court held that the FTC could not pursue the debt collection because it was time-barred under state law. The lower court reasoned that the FDCPA did not govern the debt collection, because the proceeds that the FTC sought were intended for disbursement to the defendants' victims, not the United States. On appeal, the panel majority rejected this interpretation of the FDCPA (which the First Circuit had also adopted), instead holding that, because the proceeds would immediately be paid to the FTC, the judgment constituted a "debt" under the FDCPA regardless of the ultimate disbursement to private parties (FTC v. Hoskins).
• Criminal Law & Procedure: The Fourth Circuit affirmed a criminal defendant's convictions and sentence for health-care-fraud-related offenses targeting Medicare beneficiaries, including his sentencing enhancement under § 2B1.1(b)(2)(A)(ii) of the Sentencing Guidelines for committing an offense through "mass marketing." The Guidelines define mass-marketing as a "plan, program, promotion, or campaign that is conducted through solicitation by telephone, mail, the Internet, or other means to induce a large number of persons" to, among other things, "purchase goods or services." The defendant argued that § 2B1.1(b)(2)(A)(ii) did not apply because, although he engaged in a marketing campaign that targeted Medicare beneficiaries, those individuals suffered no loss and were not victims of his conduct. Rather, the Medicare program was the only entity that sustained a loss due to his fraudulent activity. The Fourth Circuit rejected this argument, holding that the plain text of § 2B1.1(b)(2)(A)(ii) requires only that the offender targeted a large number of persons, regardless of whether they are directly harmed by the defendant's actions. In doing so, the Fourth Circuit split from the Second and Eighth Circuits, which read the Guidelines provision to focus on the offender's victims. The Fourth Circuit described its decision as consistent with rulings by the Fifth and Eleventh Circuits (United States v. Joyner).
• Criminal Law & Procedure: The Fourth Circuit created a circuit split over the meaning of 18 U.S.C. § 4243, which governs the revocation of conditional discharges from civil commitment for persons who were institutionalized after being found not guilty by reason of insanity. The lower court had revoked a former criminal defendant's conditional discharge from civil commitment after he robbed a store at gunpoint, in violation of a discharge condition that prohibited him from possessing weapons. On appeal, the Fourth Circuit joined the Eleventh Circuit in deciding that the plain text of § 4243 authorized the revocation of a conditional discharge of civil commitment only when the released individual violated a discharge condition that was part of a "prescribed regimen of medical, psychiatric, or psychological care or treatment." The controlling opinion acknowledged a split with the First, Seventh, Eighth, and Ninth Circuits, which have interpreted § 4243 and related statutes to permit recommitment of a person who violates a condition "ancillary" to those that are part of a prescribed regimen. Even under its narrower interpretation of § 4243, the Fourth Circuit panel majority held that revocation was proper because the condition the released individual violated (possessing a weapon) was part of a prescribed regimen prepared by the director of the mental health institution from which the individual was conditionally discharged (United States v. Roney).
• Criminal Law & Procedure: In denying a prisoner's motion to proceed in forma pauperis, the Fifth Circuit considered the meaning of 28 U.S.C. § 1915, which generally bars a prisoner from bringing a civil action or appealing a judgment in federal court without prepaying filing fees after three or more prior actions have been dismissed on enumerated grounds (sometimes called the "three strikes" rule). Here, the petitioner's third "strike" was the lower court proceeding in the case before the circuit court—the petitioner sought to proceed in forma pauperis in appealing the lower court's decision. The Fifth Circuit joined the Third Circuit in holding that the three strikes rule applies when the third strike itself is the subject of the appeal and disagreed with rulings by the Fourth and Ninth Circuits holding that prisoners may appeal their third strike in forma pauperis (Meeks v. Ray).
• Criminal Law & Procedure: The Fifth Circuit largely affirmed a criminal defendant's sentence under 18 U.S.C. § 2252A for committing a federal offense related to the receipt of child pornography, including a sentence enhancement because of a prior conviction under a Texas child pornography statute. A defendant convicted of a federal child pornography offense is subject to an enhanced minimum sentence under § 2252A(b)(1) if he or she had been convicted of a prior offense "relating to" the possession of child pornography, among other offenses. Although the defendant's prior Texas conviction was for an offense that covered somewhat broader conduct than the federal child pornography statute, the Fifth Circuit joined the majority of reviewing circuits that have interpreted § 2252A(b)(1)'s "relating to" language to mean that the prior offense does not have to be a perfect match to the federal crime. The court acknowledged a split with the Sixth and Ninth Circuits, which have said that a sentencing enhancement under § 2252A(b)(1) is available only if the defendant's prior state criminal law offense did not cover a broader swath of conduct than the federal child pornography offense (United States v. Mendoza).
• Criminal Law & Procedure: On remand from the Supreme Court, the Eighth Circuit held that the Ex Post Facto Clause barred the application of the Mandatory Victims Restitution Act (MVRA), which extended the enforcement period for criminal restitution obligations under 18 U.S.C. § 3613(b), to criminal defendants whose offenses were committed before the MVRA's enactment and for whom the restitution period would have expired if not for the MVRA. In reaching this conclusion, the Eighth Circuit joined the Third Circuit but split from at least two circuits (the Second and Ninth) that have held that the MVRA's extension of the enforcement period would not implicate the Ex Post Facto Clause even when applied to defendants whose restitution period would have expired but for the MVRA (United States v. Ellingburg).
• Elections: The Fourth Circuit held that a South Carolina statute authorizing absentee-by-mail voting without need provide a justification for not voting in person—but only for persons 65 years or older—violated the Twenty-Sixth Amendment. The Amendment provides that the right of U.S. citizens "who are eighteen years of age or older, to vote shall not be denied or abridged by the United States or by any State on account of age." The South Carolina statute authorizes persons 65 years or older to cast absentee votes in any election for any reason (sometimes called "no-excuse" absentee voting), while persons under 65 may cast absentee ballots only if they satisfy specific statutory criteria. The Fourth Circuit held that the statute violated the Twenty-Sixth Amendment because it established different eligibility criteria for no-excuse absentee voting based on age. Although the state law did not make voting harder for persons under 65 years of age, the Fourth Circuit did not find this constitutionally significant; what mattered, according to the court, was that the law resulted in it being harder for persons under the age of 65 to vote than for persons 65 years or older. The panel acknowledged splits with the Fifth Circuit, which holds that an election law can only abridge one's right to vote under the Twenty-Sixth Amendment if it makes it more difficult for a person to vote than before the law was enacted or enforced, and the Seventh Circuit, which looks to whether a material requirement meaningfully burdens the exercise of one's voting rights (Grant v. Belangia).
• Immigration: On a legal question the Supreme Court has agreed to take up this term, divided panels of the First and Third Circuits widened a circuit split over when an alien taken into immigration custody after unlawfully entering the country may be detained without bond during removal proceedings. Under federal statute, an alien often may be released from custody on bond or on the alien's own recognizance while removal proceedings are pending. Except in narrow circumstances, however, 8 U.S.C. § 1225(b)(2)(A) directs that, "in the case of an alien who is an applicant for admission, if the examining immigration officer determines that an alien seeking admission is not clearly and beyond a doubt entitled to be admitted, the alien shall be detained [during removal proceedings]" (emphasis added). Federal statute provides that an alien "present in the United States who has not been admitted" shall be treated as an "applicant for admission," but it does not define an "alien seeking admission." The Fifth and Eighth Circuits have treated "applicant for admission" and "alien seeking admission" as synonymous, meaning that aliens present in the United States but not lawfully admitted are subject to mandatory detention under § 1225(b)(2)(A). A divided First Circuit disagreed, joining several other circuits—the Second, Sixth, Seventh, Ninth, Tenth, and Eleventh—that previously held that an "alien seeking admission" under § 1225(b)(2)(A) is not synonymous with an "applicant for admission," and that § 1225(b)(2)(A) mandates detention only for unlawfully present aliens who are actively seeking lawful admission into the country. The First Circuit further held that the named alien petitioner's application for cancellation of removal after being placed in removal proceedings did not mean he was "seeking admission" under § 1225(b)(2)(A). The court reasoned that the alien's application for relief from removal was distinct from seeking lawful admission into the country. A few weeks later, a divided Third Circuit panel similarly held that § 1225(b)(2)(A) did not apply to aliens who entered the United States several years earlier and were not actively seeking admission into the United States. Unlike some other panels who decided similar challenges on statutory grounds, the Third Circuit panel majority also held that the mandatory detention of aliens who lived in the United States for extended periods and had no criminal records violated the Due Process Clause (First Circuit: Guerrero Orellana v. Moniz, Third Circuit: Buele Morocho v. Warden Philadelphia FDC).
• Immigration: The Fourth Circuit held that an alien was not inadmissible and removable from the United States on account of being "convicted of" an enumerated offense under 8 U.S.C. § 1182(a)(2)(A)(i) when the underlying conviction had been vacated. In so doing, the circuit panel rejected the long-standing interpretation of the Board of Immigration Appeals (BIA) and overturned circuit precedent that had afforded Chevron deference to the BIA's interpretation. Under the BIA's long-standing interpretation, a conviction vacated because of a substantive or procedural defect would not qualify as a conviction for immigration purposes but would qualify if vacated for any other reason. Because the Supreme Court in Loper Bright Enterprises v. Raimondo overruled the Chevron doctrine that afforded judicial deference to agency interpretation of ambiguous statutes, the Fourth Circuit looked to the text of the statute and concluded that the best reading barred a vacated conviction from qualifying as a conviction for immigration purposes no matter the reason for the vacatur. In so doing, the court observed that it split from the First, Second, Third, Sixth, Seventh, Eighth, Ninth, and Tenth Circuits, which agreed with the BIA's position. The court also observed a split from the Fifth Circuit, which took the opposite view and held that a conviction always carries immigration consequences regardless of whether it is vacated (Yanez Piedra v. Blanche).
• Immigration: A divided Fourth Circuit widened two separate circuit splits involving 8 U.S.C. § 1252, which governs judicial review of "final" orders of removal. The petitioner had a prior removal order reinstated after reentering the United States and, in administrative proceedings, was then denied withholding of removal under 8 U.S.C. § 1231(b)(3)(A) and relief under the Convention Against Torture (CAT). The petitioner conceded his removability under the reinstated removal order but sought review of his withholding and CAT claims under 8 U.S.C. § 1252(a)(1), which grants federal appellate courts jurisdiction to review final orders of removal. Agreeing with the Third Circuit but disagreeing with the Ninth and Eleventh Circuits, the Fourth Circuit panel majority ruled that § 1252(a) did not deprive it of jurisdiction to review the denial of withholding of removal and CAT claims even when the petitioner did not challenge his underlying removability. The panel then considered whether the petitioner's claims were time-barred. Under 8 U.S.C. § 1252(b)(1), a final order of removal must be appealed to a U.S. circuit court within 30 days. Here, the petitioner sought appellate review more than 30 days after his reinstated removal order but within 30 days of his request for CAT relief and withholding of removal being denied. After the petitioner filed his appeal, the Supreme Court, in Riley v. Bondi, held that the 30-day clock is tied to the final administrative order deciding that the alien is removable, not to the conclusion of any subsequent administrative proceedings concerning the alien's eligibility for relief. The Fourth Circuit panel majority held that, under Riley, the statutory deadline for seeking appellate review was trigged by reinstatement of the petitioner's removal order. Expressing disagreement with a Fifth Circuit opinion but endorsing the views of the Sixth and Seventh Circuits, the court held that § 1252(b)(1)'s deadline may be equitably tolled when the alien pursued his or her rights diligently and the delay resulted from extraordinary circumstances beyond the petitioner's control. Such tolling allowed the court to consider the petitioner's claim, the majority held, because his late filing was due to his reliance on judicial precedent abrogated by Riley. Turning to the merits, the majority vacated the administrative determination that the petitioner was ineligible for withholding of removal and CAT relief and remanded the case for further proceedings (Navarro Cerritos v. Blanche).
• Securities: The Seventh Circuit affirmed a lower court's dismissal of a lawsuit brought by investors who alleged that the defendant deceived the securities market through "channel stuffing," a practice by which a seller foists inventory on distributors to create a false appearance of greater profitability. The plaintiffs brought claims under both the Securities Exchange Act of 1934 (the Exchange Act) and the Securities Act of 1933 (Securities Act). The Exchange Act claims were subject to the heightened pleading burden requirements under the Private Securities Litigation Reform Act (PSLRA) of 1995 for securities fraud claims brought by private parties. The circuit court concluded, among other things, that the plaintiffs failed to adequately allege that the defendant's actions gave rise to strong inference of an intent to deceive the market, a requisite under the PSLRA. Securities Act claims, in contrast, do not require proof of fraudulent intent, and the plaintiffs disclaimed any reliance on fraud for these claims in favor of negligence and strict liability. The circuit court nevertheless held that the plaintiffs were subject to an elevated pleading standard under Federal Rule of Civil Procedure 9(b), which imposes a higher burden for claims alleging fraud, and failed to meet that standard. The court explained that whether Rule 9(b) applies depends on the allegations of the complaint. The Seventh Circuit joined the Second, Third, Fourth, and Ninth Circuits—and parted ways with the Fifth and Eighth Circuits—to hold that, where plaintiffs rely on the same alleged course of conduct to bring securities fraud claims under the relevant portions of the Exchange Act and claims under the Securities Act, the allegations premised on fraud and the Securities Act claims are subject to Rule 9(b), notwithstanding plaintiffs' express disavowal of fraud theories for those claims (Hunter v. Elanco Animal Health Inc.).
• Securities: The Ninth Circuit affirmed a lower court's dissolution of a preliminary injunction blocking Nevada from enforcing state gaming laws against Kalshi, a prediction markets platform. The circuit court agreed with the lower court that application of the Nevada gaming laws to Kalshi's sport events contracts was likely not preempted by the Commodity Exchange Act (CEA). The CEA gives the Commodity Futures Trading Commission (CFTC) exclusive jurisdiction over "transactions involving swaps . . . traded or executed on" a designated contract market (DCM). Although Kalshi is a regulated DCM and the Ninth Circuit agreed with Kalshi that the CEA expressly preempts state law regulating swaps traded on a DCM, the court held that Kalshi's sports event contracts were not "swaps" under the CEA and so were subject to state regulation. The Ninth Circuit rejected the argument—which the Third Circuit had previously endorsed—that Kalshi's sports events contracts met one part of the CEA's definition of "swap," which covers "any agreement . . . that provides for any purchase, sale, payment, or delivery . . . that is dependent on the occurrence, nonoccurrence, or the extent of the occurrence of an event or contingency associated with a potential financial, economic, or commercial consequence" (emphasis added). The Ninth Circuit reasoned that the CEA's context made clear that the definition of "swap" was intended to address financial risk-hedging interests and that Kalshi's broader reading of "swap" to cover contracts predicting any "event" with potential financial consequences had no limiting principle and raised concerns under the major questions doctrine. The panel also ruled that 17 C.F.R. § 40.11(a), which bars a registered DCM from listing a contract that "involves, relates to, or references . . . gaming," provided an additional basis to affirm the lower court's ruling. (The CFTC has proposed revisions to the regulation that would remove this categorical prohibition.) The Ninth Circuit remanded the case to district court to consider in the first instance Nevada's challenges to Kalshi's contracts concerning elections. The Sixth Circuit has since deepened the circuit split by concluding that Kalshi's sports event contracts are subject to state regulation on somewhat different grounds (KalshiEx, LLC v. Assad).
• Separation of Powers: A divided Second Circuit affirmed a district court's decision to quash grand jury subpoenas obtained by John Sarcone, the purported Acting U.S. Attorney for the Northern District of New York, after concluding he was not lawfully exercising the duties of that office. In July 2025, Sarcone was appointed as a "Special Attorney," designated as the First Assistant U.S. Attorney (FAUSA) for the district, and authorized in that role to conduct "any kind of legal proceedings" that U.S. Attorneys "are authorized to conduct." The Department of Justice (DOJ) claimed that, as the FAUSA, Sarcone could then serve as Acting U.S. Attorney pursuant to the Federal Vacancies Reform Act of 1998 (FVRA). The FVRA authorizes specific categories of officials to perform temporarily the functions and duties of certain vacant offices, including U.S. Attorney positions. As relevant here, the FVRA provides that if a covered officer "dies, resigns, or is otherwise unable to perform the functions and duties of the office, . . . the first assistant to the office of such officer shall perform the functions and duties of [that] office" for a prescribed period. The Second Circuit held that the FVRA only authorizes a first assistant to serve in an acting capacity if he or she was already in that role at the time the U.S. Attorney's office became vacant. Among other factors, the court emphasized the "automaticity" of the statutory text, ruling that it operates at the time the vacancy occurs. The DOJ argued in the alternative that it had lawfully delegated subpoena authority to Sarcone in his roles as First Assistant and Special Attorney. The panel majority rejected this argument, holding that, because the FVRA states that it is "the exclusive means for temporarily authorizing" acting service, the law barred the "wholesale delegation" of the U.S. Attorney's functions to Sarcone. The panel majority's interpretation of the FVRA is consistent with Third and Ninth Circuit rulings on Acting U.S. Attorneys in New Jersey and Nevada. All three circuits, however, disagreed with an earlier decision of the Federal Circuit that had concluded the FVRA did not bar such a delegation (In re Grand Jury Subpoenas to the Off. of the N.Y. Att'y Gen.).