There are a handful of ways to lose a Minnesota lawsuit without anyone ever looking at whether you were wronged. The expert affidavit is the most unforgiving of them.
If you sue a doctor, a lawyer, an accountant, an architect, or an engineer in Minnesota, you do not simply file a complaint. You must also produce a sworn statement from a qualified expert saying your case has merit — and you must produce it on a schedule that starts running before you have taken a single deposition. Miss it, and the statute does not invite the court to consider excusing you. It says the case is dismissed.
On January 20, 2026, the Supreme Court held that a requirement of exactly this kind does not apply in federal court.
Minnesota was on the losing side of that argument, by choice.
What Minnesota requires
Two statutes do the work, and they are close cousins.
Minn. Stat. § 145.682 governs malpractice actions against health-care providers. It requires two affidavits. The first must be served with the summons and complaint, stating that the plaintiff’s attorney has reviewed the facts with a qualified expert and that the expert believes a defendant deviated from the standard of care and caused injury. The second, identifying the experts who will testify and summarizing their opinions and the grounds for them, is due within 180 days after discovery commences.
Minn. Stat. § 544.42 does the same for other licensed professionals — attorneys, architects, certified public accountants, engineers, land surveyors, and landscape architects. Same structure, same two affidavits, same clock.
And the same consequence. The penalty provision in each statute is not permissive:
“Failure to comply … results, upon motion, in mandatory dismissal of each cause of action with prejudice as to which expert testimony is necessary to establish a prima facie case.”
Mandatory. With prejudice. Not a continuance, not a chance to cure at the court’s discretion. There are narrow relief valves — § 544.42 gives a plaintiff 60 days after a demand to produce the first affidavit, and requires notice and a 60-day cure period for certain deficiencies in the second — but the architecture is designed to end cases early and permanently.
The policy behind it is not mysterious. These statutes are screening mechanisms, enacted to keep weak professional-liability claims from reaching discovery, on the theory that malpractice insurance costs everyone money. Whatever one thinks of that trade, it is a legislative judgment the Legislature was entitled to make.
The question the Supreme Court just answered is a different one: does that judgment travel with the claim into federal court?
Berk v. Choy
Harold Berk fell out of bed while traveling in Delaware. He was taken to a hospital, an X-ray showed a fractured ankle, and a doctor recommended a protective boot. According to his complaint, hospital employees forced his leg into the boot and twisted the fractured ankle. No new X-ray was ordered that day. Two weeks later a second X-ray showed the ankle was not merely fractured but severely deformed, and surgery followed.
Berk sued the doctor and the medical center. Because he and the defendants were citizens of different states, he was able to sue in federal court.
Delaware, like Minnesota, requires an affidavit of merit to accompany a malpractice complaint. Berk moved for an extension, spent the extension trying to find a doctor willing to sign — an effort the Court noted “spawn[ed] separate litigation” of its own — and came up empty. He filed his medical records under seal instead and argued that the Delaware statute could not be enforced in federal court because the Federal Rules of Civil Procedure already answered the question.
The district court dismissed. The Third Circuit affirmed, reasoning that the Federal Rules were silent and that Delaware’s law was “substantive” under Erie.
The Supreme Court reversed. Justice Barrett wrote for eight members of the Court; Justice Jackson concurred in the judgment.
The reasoning is short and, once stated, hard to unsee. Federal Rule of Civil Procedure 8 already tells a plaintiff what he must put in front of the court at the outset of a case: “a short and plain statement of the claim showing that [he] is entitled to relief.” By requiring no more than a statement of the claim, the Court said, Rule 8 establishes “implicitly, but with unmistakable clarity,” that evidence of the claim is not required at the pleading stage. Rule 12 reinforces it, supplying exactly one merits-based ground for dismissal and forbidding courts from considering “matters outside the pleadings” in deciding it.
Delaware’s statute and Rule 8 therefore answered the same question and gave different answers. When that happens, the Federal Rule governs, so long as it is valid — and Rule 8, the Court held, plainly “really regulates procedure.”
The defendants had a fallback: read the Delaware statute not as a pleading rule but as a free-floating evidentiary requirement. The Court rejected it, pointing out that the Federal Rules already have a mechanism for making a plaintiff prove his case before trial. It is called summary judgment, and it is Rule 56.
The Minnesota detail
Tennessee led an amicus brief urging the Court to affirm — that is, urging it to hold that state affidavit statutes do apply in federal court. Twenty-six other state attorneys general signed on, twenty-seven states in all.
Minnesota’s Attorney General was among them.
That is not a criticism; it is the ordinary institutional position of a state’s chief legal officer, who has an interest in seeing his Legislature’s enactments given effect wherever the claim is filed. But it tells you something about how the state understood the stakes. Minnesota did not regard this as a technical question about Delaware. It regarded it as a question about whether §§ 145.682 and 544.42 mean what they say when a Minnesota plaintiff walks into the federal courthouse in Minneapolis or St. Paul instead of the state courthouse across the street.
The Court’s answer to the Delaware version of that question was no.
What this does and does not change in Minnesota
I want to be careful here, because this is precisely the kind of decision that gets over-read into malpractice.
It does not change anything in state court. The overwhelming majority of Minnesota professional-liability cases are filed in Hennepin, Ramsey, or another Minnesota district court, and in those courts §§ 145.682 and 544.42 apply with full force. Nothing in Berk touches them. If your case is in state court, the affidavit deadlines are exactly as real today as they were in December.
It applies only where there is a federal forum. That means diversity of citizenship — parties from different states, with enough in controversy — or a federal claim to hang the case on. Two Minnesotans disputing Minnesota malpractice in Minnesota have no federal forum, and the question never arises.
No court has yet applied Berk to Minnesota’s statutes. The reasoning maps onto them closely: the first affidavit under each statute is expressly tied to the pleading, served “with the summons and complaint” or “with the pleadings,” which is the same structural feature that made Delaware’s law collide with Rule 8. But the Eighth Circuit has not said so, and federal courts sitting in Minnesota enforced § 145.682 for decades before January.
The second affidavit is a genuinely different question. The expert-disclosure affidavit due 180 days after discovery commences is not attached to a pleading at all. It looks much more like an expert-disclosure obligation, and the Federal Rules have their own machinery for that in Rule 26. Whether it survives Berk is a separate argument from whether the first one does, and it deserves to be briefed separately rather than assumed.
And nobody should skip an affidavit on the strength of a blog post. If you guess wrong about which forum you are in or how a court will read the statute, the sanction is dismissal with prejudice, and by the time you find out, the statute of limitations has usually run. The prudent course after Berk is not to stop preparing affidavits. It is to understand that a plaintiff who genuinely cannot obtain one in time may now have an argument he did not have before — and that where the case belongs is a question worth thinking hard about at the outset rather than after a dismissal.
The larger point
There is a version of civil procedure that treats these questions as housekeeping. It is not.
Minnesota’s affidavit statutes decide cases. A claim that a jury would have found meritorious can end because a busy expert did not return a call inside a statutory window, and the dismissal is with prejudice, which means it ends forever. When a rule has that much power, the question of where the rule applies is not a technicality — it is often the whole case.
What Berk holds is narrow and, in a way, modest: when the Federal Rules have already answered a question, a state answer to the same question does not displace them in federal court. It does not say Minnesota’s screening policy is bad, and it does not say a plaintiff should be able to sue a doctor on nothing. It says Rule 8 already decided what a complaint has to contain, and Rule 56 already decided when a plaintiff gets put to his proof.
For most Minnesota plaintiffs, nothing changes. For the ones with a federal forum and a real case they could not get sworn to in ninety days, something just did.
If you are facing a professional-liability claim — or an affidavit deadline you are not sure you can meet — the forum question is worth raising early rather than late. Send us a message or call 612-470-6529.
Sources: Berk v. Choy, 607 U. S. 187 (2026) (Barrett, J.), No. 24–440, decided January 20, 2026; Minn. Stat. §§ 145.682, 544.42 (2025); Fed. R. Civ. P. 8, 12, 56. This article is general commentary on a published decision and on Minnesota statutes, not legal advice, and reading it does not create an attorney–client relationship. Whether any particular affidavit requirement applies to any particular case depends on facts and on the forum. No outcome is promised or implied.