I’ve watched defendants run this play for years. On February 24, 2026, a unanimous Supreme Court took it away.
The setup is about as ordinary as Minnesota product-liability practice gets. Someone gets hurt by a product. They sue two defendants: the out-of-state company that made it and the Minnesota business that sold it. Both are real defendants with real potential liability. And because one of them shares the plaintiff’s citizenship, the case can’t go to federal court.
So the manufacturer removes anyway. It argues the local defendant was “improperly joined,” gets the federal judge to dismiss that defendant, and then says: look, complete diversity now exists, we are properly here.
That doesn’t work anymore.
What happened in Palmquist
The Palmquists sued the Hain Celestial Group over a product and joined Whole Foods Market, a non-diverse defendant. Hain removed to federal court on diversity grounds. The Palmquists promptly moved to remand. The district court didn’t send it back. It invoked the doctrine of improper joinder, dismissed Whole Foods, kept the case, and eventually entered judgment for Hain.
The Fifth Circuit reversed the improper-joinder ruling and vacated the judgment for lack of jurisdiction. The Supreme Court affirmed, 9–0, in an opinion by Justice Sotomayor.
Here’s the holding in plain words. If a federal court wrongly dismisses a non-diverse party after removal, that doesn’t let it exercise diversity jurisdiction, and the case has to go back to state court. The jurisdiction problem that existed the moment the case was removed doesn’t get fixed by trimming off the party that caused it.
Read this sentence from the Court twice. I did:
The Palmquists exercised their right to choose a state forum by purposefully and properly joining a nondiverse defendant against whom they could not proceed in federal court, and diligently asserted that right by promptly moving to remand the case to state court.
Federal Rule of Civil Procedure 21 — the rule that lets courts add or drop parties — “does not permit a court or a defendant to override their choice in these circumstances.”
Justice Thomas wrote separately. He’s skeptical of the improper-joinder doctrine itself, noting that it seems to let federal courts enlarge their own jurisdiction by weighing the merits of claims they have no jurisdiction over. That’s a shot across the bow at a doctrine that’s never had a clean home in the statute books.
The plaintiffs earned this one
The holding isn’t “plaintiffs always win the forum fight.” Go back to the Court’s sentence and you’ll find two conditions doing real work.
“Purposefully and properly joining.” The local defendant has to be a genuine defendant. A Minnesota retailer named only as a jurisdictional speed bump, with no plausible claim against it, is exactly what the improper-joinder doctrine is there to catch. Palmquist does not protect that. It protects a real claim against a real local party.
“Diligently asserted . . . by promptly moving to remand.” The Palmquists didn’t sit on it. A plaintiff who lets the case settle into federal court for months and then finds a jurisdictional objection is in a much weaker spot than one who files the remand motion on schedule.
You need both. The Court protected a right, and you protect a right by using it on purpose and on time.
A Minnesota case in everything but the caption
My clients join local defendants all the time, and usually for reasons that have nothing to do with federal jurisdiction. Someone hurt on a premises sues the out-of-state parent and the Minnesota operating entity. A borrower sues the national lender and the Minnesota servicer. A buyer sues the out-of-state supplier and the Minnesota distributor that handled the goods.
Product cases get a specific warning, because Minnesota law cuts against the idea that a local retailer is a co-defendant you can count on keeping. Minnesota has adopted strict liability in tort, but it has also enacted Minn. Stat. § 544.41, which limits the liability of non-manufacturers. A defendant other than the manufacturer must, on answering, file an affidavit certifying the manufacturer’s correct identity — and once the manufacturer has answered, the statute says the court “shall order the dismissal” of the strict-liability claim against the certifying seller. “Shall,” not “may.”
There are exceptions, in subdivision 3: the seller stays in if the plaintiff shows it exercised significant control over design or manufacture, provided instructions or warnings to the manufacturer, had actual knowledge of the defect, or created the defect. And subdivision 2 allows reinstatement if the manufacturer turns out to be time-barred, misidentified, defunct, unservable, beyond jurisdiction, or unable to satisfy a judgment.
So in Minnesota, “sue the store too” depends on the facts. It isn’t automatic. And a removing manufacturer can point to § 544.41 to build an improper-joinder argument at the removal stage. Palmquist doesn’t answer that argument. It answers what happens after a district court gets improper joinder wrong.
What Palmquist adds is this: when the joinder is real — a real claim against a real local party — your choice of courthouse survives the other side’s attempt to test it.
It also pairs with something else from this term. Two months later, in Enbridge Energy, LP v. Nessel, the Court held that the 30-day removal deadline can’t be equitably tolled. Put the two together and I read October Term 2025’s message on getting into federal court as pretty blunt: a defendant who wants a federal forum has to establish it correctly, and fast. You can’t manufacture it after the fact, and you can’t claim it late.
What I take from it in practice
If you’re a plaintiff. Your choice of a Minnesota state courtroom holds up better than it used to. But it depends on your local defendant being a real one and on moving to remand promptly. You make both of those calls in the first month of a case, not the sixth.
If you’re a defendant. You now have to win the improper-joinder argument at the front end, at removal, on the record as it stands at removal. And getting it wrong is brutal. Palmquist went through a federal jury trial that ended in judgment as a matter of law for Hain when the plaintiffs rested — the defendant won — and all of it was vacated for want of jurisdiction. Years of litigation expense, turned into a fresh start in the state court the plaintiffs picked at the beginning. In our circuit, that used to come out the other way: in Junk v. Terminix International Co., 628 F.3d 439 (8th Cir. 2010), the Eighth Circuit let a judgment for the diverse defendants stand even after holding the local defendant had been wrongly dismissed, and that’s the side of the split the Supreme Court just rejected.
That isn’t a technicality. It’s the most expensive procedural mistake you can make in civil litigation, and the Court just made it harder to survive.
Federal courts are courts of limited jurisdiction. Lawyers say that so often it stops meaning anything. Palmquist is what it actually means: a federal court either has power over a case or it doesn’t, measured the moment the case shows up, and no amount of case management later creates power that wasn’t there at the door.
If you were hurt in Minnesota by an out-of-state company’s product, here’s the plain-English version: if you have a real claim against a Minnesota defendant, the other side doesn’t get to undo your decision to file here by getting that defendant dismissed later. Whether you have that real claim — especially against a retailer, given § 544.41 — is the question I want answered before filing, not after.
If you’ve been served with a notice of removal, or you’re deciding where to bring a claim involving both a Minnesota business and an out-of-state company, the forum decision gets made early and it’s hard to undo. Send us a message or call 612-470-6529.
Sources: Hain Celestial Group, Inc. v. Palmquist, 607 U. S. 421 (2026) (Sotomayor, J.), No. 24–724, decided February 24, 2026 (Thomas, J., concurring), affirming and remanding; Junk v. Terminix Int’l Co., 628 F.3d 439 (8th Cir. 2010); Fed. R. Civ. P. 21; 28 U.S.C. §§ 1332, 1441, 1447; Minn. Stat. § 544.41 (limit on liability of nonmanufacturers); Enbridge Energy, LP v. Nessel, 608 U. S. 67 (2026). This article is general commentary on a published decision and federal statutes and rules, not legal advice, and reading it does not create an attorney–client relationship. Whether joinder of a particular defendant is proper, and whether a remand motion is timely, depends entirely on the facts of the case. No outcome is promised or implied.