Minnesota has a certificate-of-merit regime. It is not called that, it is not in one place, and it functions as an early screen on the merits in exactly the case types where expert proof is most expensive to obtain.
Two statutes do the work. Minn. Stat. § 544.42 covers actions against licensed professionals. Minn. Stat. § 145.682 covers malpractice actions against health care providers. Each requires two sworn filings on a schedule, and each says that failure results, on motion, in mandatory dismissal with prejudice of every cause of action requiring expert testimony.
Here is the part that catches people, and it is the reason this page exists: neither of the deadlines that matters runs from anything a court does. One runs from the day your opponent serves a demand. The other runs from the day the parties themselves confer and prepare a discovery plan. A firm that manages deadlines off the docket will not see either clock start.
When do these statutes apply at all?
Read the triggering language carefully, because the two statutes are not phrased the same way.
Section 544.42, subd. 2 applies:
In an action against a professional alleging negligence or malpractice in rendering a professional service where expert testimony is to be used by a party to establish a prima facie case . . .
Section 145.682, subd. 2 applies:
In an action alleging malpractice, error, mistake, or failure to cure, whether based on contract or tort, against a health care provider which includes a cause of action as to which expert testimony is necessary to establish a prima facie case . . .
One says expert testimony “is to be used by a party.” The other says it “is necessary.” Those are not the same condition, and the difference is worth thinking about at the threshold of a case that may or may not need an expert at all.
Who counts as a “professional”?
Section 544.42’s list is closed and short. Subdivision 1:
(1) “professional” means a licensed attorney or an architect, certified public accountant, engineer, land surveyor, or landscape architect licensed or certified under chapter 326 or 326A; and
(2) “action” includes an original claim, cross-claim, counterclaim, or third-party claim. An action does not include a claim for damages requiring notice pursuant to section 604.04.
Six categories. That is the whole list. A great many people the world calls professionals are not on it — and the first question in any negligence case against a service provider is whether the defendant is inside the definition, because if the answer is no, § 544.42 imposes nothing.
And notice clause (2). “Action” includes a counterclaim. A defendant who answers a fee suit with a malpractice counterclaim against the plaintiff professional is a party asserting an “action” under this statute and is subject to its affidavit requirements. That is a common and expensive surprise.
Section 145.682’s definition runs the other direction — it is broad and incorporates other statutes. Subdivision 1:
For purposes of this section, “health care provider” means a physician, surgeon, dentist, or other health care professional or hospital, including all persons or entities providing health care as defined in section 145.61, subdivisions 2 and 4, or a certified health care professional employed by or providing services as an independent contractor in a hospital.
Those cross-references have to be read directly. Section 145.61, subd. 2 defines “professional” as “a person licensed or registered to practice a healing art under chapter 147 or 148, to practice dentistry under chapter 150A, to practice as a pharmacist under chapter 151, or to practice podiatry under chapter 153,” and subd. 4 defines “health care” as “professional services rendered by a professional or an employee of a professional and services furnished by a hospital, sanitarium, nursing home or other institution for the hospitalization or care of human beings.”
The first affidavit, and the deadline that lives on your opponent’s desk
Both statutes require an affidavit of expert review served with the initial pleading. Section 544.42, subd. 3(a) requires that it “be drafted by the party’s attorney” and state:
(1) the facts of the case have been reviewed by the party’s attorney with an expert whose qualifications provide a reasonable expectation that the expert’s opinions could be admissible at trial and that, in the opinion of this expert, the defendant deviated from the applicable standard of care and by that action caused injury to the plaintiff;
Section 145.682, subd. 3(1) is nearly identical, substituting “one or more defendants” for “the defendant.”
Both statutes then provide an escape hatch for the plaintiff who filed against a running limitations clock. Under § 544.42, subd. 3(a)(2) and § 145.682, subd. 3(2), the affidavit may instead state that expert review “could not reasonably be obtained before the action was commenced because of the applicable statute of limitations” — in which case the real affidavit must be served within 90 days after service of the summons and complaint. Section 544.42, subd. 3(b); § 145.682, subd. 3(2).
Now the sanction, and the trigger. Both statutes, at subdivision 6(a):
Failure to comply with subdivision 2, clause (1), within 60 days after demand for the affidavit 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.
(Section 145.682, subd. 6(a) reads the same, with “mandatory dismissal with prejudice of each cause of action.”)
Read that against the requirement it enforces. Subdivision 2, clause (1) says the affidavit is served “with the pleadings” — or, in § 145.682, “with the summons and complaint.” But the dismissal sanction is not triggered by the passage of time from filing. It is triggered by a demand, and then sixty days.
The consequence is straightforward and unpleasant. A plaintiff who filed without the affidavit is not safe because months have passed without incident. The defendant holds the trigger. Serve a demand, wait sixty days, move to dismiss — and the statute says the dismissal is mandatory and with prejudice as to every claim requiring expert proof. In a case where the limitations period has since run, “with prejudice” means permanently.
There is no way to calendar a deadline that has not started. What can be calendared is the day the demand arrives, and the sixty days from it, and firms that handle these cases should have a docketing rule that treats a § 544.42 or § 145.682 demand as a red-flag intake the day it is received.
The second affidavit, and the clock the parties start themselves
Both statutes require a second affidavit — of expert disclosure or identification — within 180 days after commencement of discovery under Minn. R. Civ. P. 26.04(a). Section 544.42, subd. 2(2); § 145.682, subd. 2(2).
So look at Rule 26.04(a):
(a) Timing. Notwithstanding the provisions of Rules 26.02, 30.01, 31.01(a), 33.01(a), 36.01, and 45, parties may not seek discovery from any source before the parties have conferred and prepared a discovery plan as required by Rule 26.06(c) except in a proceeding exempt from initial disclosure under Rule 26.01(a)(2), or when allowed by stipulation or court order.
Discovery commences when the parties confer and prepare a discovery plan. That is a party-scheduled event. It does not generate a court filing on its own, it can happen by telephone, and it is entirely possible for two lawyers to disagree afterward about the date it occurred.
A 180-day mandatory-dismissal clock hanging off a date that exists only in the lawyers’ memories is a bad combination. The remedy is cheap: confirm the date of the Rule 26.06(c) conference in writing, by email, the day it happens, and calendar 180 days from it in the file.
Content differs between the two statutes, and the difference is operational:
- Section 544.42, subd. 4(a) requires the affidavit to be “signed by the party’s attorney” and to state the identity of each expert expected to testify on negligence, malpractice, or causation, “the substance of the facts and opinions to which the expert is expected to testify, and a summary of the grounds for each opinion.” Interrogatory answers satisfy it “if they are signed by the party’s attorney and served upon the opponent within 180 days after commencement of discovery.”
- Section 145.682, subd. 4(a) requires the affidavit to be “signed by each expert listed in the affidavit and by the plaintiff’s attorney,” with the same content. Interrogatory answers satisfy it only if “signed by the plaintiff’s attorney and by each expert listed in the answers.”
Getting a treating physician or a retained medical expert to physically sign a document is a materially different logistical problem from signing it yourself. Section 145.682 imposes that problem; § 544.42 does not.
Section 145.682 adds subdivision 4(c), which applies specifically “[i]n any action alleging medical malpractice”: all expert interrogatory answers must be signed by the responding party’s attorney and by each expert listed; the court “shall include in a scheduling order a deadline prior to the close of discovery for all parties to answer expert interrogatories for all experts to be called at trial”; and “[n]o additional experts may be called by any party without agreement of the parties or by leave of the court for good cause shown.”
Where the twins are not twins
Practitioners treat these statutes as the same statute applied to different defendants. On the four points that actually decide motions, they are not.
| § 544.42 (attorneys, architects, CPAs, engineers, land surveyors, landscape architects) | § 145.682 (health care providers) | |
|---|---|---|
| Good-cause waiver of expert review | Yes — subd. 3(c). On an application “served with commencement of the action,” the court may waive or modify the certification for good cause, “includ[ing] . . . a showing that the action requires discovery to provide a reasonable basis for the expert’s opinion or the unavailability, after a good faith effort, of a qualified expert at reasonable cost” | No such provision in the statute |
| Who signs the disclosure affidavit | The party’s attorney (subd. 4(a)) | The party’s attorney and each expert listed (subd. 4(a)) |
| Cure for a deficient disclosure affidavit | On an initial motion, dismissal “shall not be granted unless, after notice by the court, the nonmoving party is given 60 days to satisfy the disclosure requirements,” and “the court shall issue specific findings as to the deficiencies” (subd. 6(c)) | Dismissal requires that the motion “identifies the claimed deficiencies,” that the hearing be “at least 45 days from the date of service of the motion,” and that the plaintiff not serve a corrected affidavit or answers before the hearing (subd. 6(c)) |
| Sanction for a bad-faith certification | “reasonable attorney’s fees, costs, disbursements, and other damages that may be determined by the court” (subd. 7) | “reasonable attorney fees, costs, and disbursements” (subd. 7) |
| Who is bound | Any party asserting an “action,” expressly including a counterclaim, cross-claim, or third-party claim (subd. 1(2)) | Written in terms of “the plaintiff” (subds. 2, 3, 4) |
| Extensions | “The parties by agreement, or the court for good cause shown, may provide for extensions of the time limits specified in subdivision 2, 3, or this subdivision” (subd. 4(b)) | “The parties or the court for good cause shown, may by agreement, provide for extensions of the time limits specified in subdivision 2, 3, or this subdivision” (subd. 4(b)) |
The waiver asymmetry is the largest one. A lawyer suing an engineer can apply, at commencement, for a waiver or modification on the ground that the case “requires discovery to provide a reasonable basis for the expert’s opinion” or that a qualified expert is unavailable at reasonable cost after a good faith effort. The statute even provides for what happens next: “If the court waives or modifies the expert review requirements, the court shall establish a scheduling order for compliance or discovery.” Section 544.42, subd. 3(c).
A lawyer suing a hospital has no corresponding provision in § 145.682 to point to.
One drafting gap worth flagging in § 544.42, subd. 3(c): the sentence governing a denied waiver reads, “If the court denies a request for a waiver under this subdivision, the plaintiff must serve on the defendant the affidavit required under subdivision 2, clause (1), within 60 days, and the affidavit required under subdivision 2, clause (2), within 180 days.” The statute does not say what event those periods run from. That is not a question to resolve by assumption when the sanction under subdivision 6(b) is mandatory dismissal with prejudice — it is a question to raise with the court in the order denying the waiver, so that the order fixes the dates.
The third screen, which is not a dismissal screen at all
Go back to § 544.42, subd. 1(2): “An action does not include a claim for damages requiring notice pursuant to section 604.04.”
Section 604.04 is Minnesota’s product-liability notice statute, and it is a merits screen of a different kind:
The attorney for a person who intends to claim damage for or on account of personal injury, death or property damage arising out of the manufacture, sale, use or consumption of a product shall cause to be presented a notice of possible claim stating the time, place and circumstances of events giving rise to the claim and an estimate of compensation or other relief to be sought. This notice shall be given within six months of the date of entering into an attorney-client relation with the claimant in regard to the claim. Notice shall be given to all persons against whom the claim is likely to be made.
Six months from the date the attorney-client relationship was entered into. Not from the injury, not from filing, not from any court event — from a fact known only to the lawyer and the client. It is the purest example of the pattern this page is about.
But the sanction is completely different, and this is the part worth understanding. Section 604.04, subd. 3:
Any person injured by the failure of a claimant or the claimant’s attorney or of a person in the chain of manufacture and distribution to comply with the requirements of this section may recover damages, costs and reasonable attorney fees from a person who violated this section, but failure to give notice does not affect the validity of a claim against a party who did not receive notice.
The claim survives. What is at risk is not the case — it is a damages, costs, and fee exposure that runs against the claimant or the claimant’s attorney. The statute also imposes a reciprocal duty on the defense side: “Any person in the chain of manufacture and distribution shall promptly furnish to the claimant’s attorney the names and addresses of all persons the person knows to be in the chain of manufacture and distribution if requested to do so by the attorney at the time the notice is given,” with the same liability provision for failure.
And the statute recognizes that formality is not the point: “Actual notice of sufficient facts to reasonably put a person against whom the claim is to be made or the person’s insurer on notice of a possible claim satisfies the notice requirements of this section.”
So Minnesota built three early screens with three different sanctions: dismissal with prejudice under § 544.42 and § 145.682, and personal exposure — without dismissal — under § 604.04. Whether a case falls inside one and outside another turns on the identity of the defendant.
What to do
- Decide, at intake, whether the defendant is inside § 544.42’s six-category list or § 145.682’s health-care definition. If neither, no affidavit is required by either statute. If both could apply, plan for the stricter one.
- Treat the affidavit of expert review as part of the complaint package, not a follow-up task. Both statutes contemplate service with the pleading. Everything else in this area is a fallback.
- If you must use the limitations exception, put the 90-day date in the file the day you file. Section 544.42, subd. 3(b) and § 145.682, subd. 3(2) both measure it from service of the summons and complaint.
- In a § 544.42 case, decide about the good-cause waiver before you commence. The application must be “served with commencement of the action.” It is not available later, and § 145.682 has no equivalent at all.
- Confirm the Rule 26.06(c) discovery conference date in writing the day it occurs, and calendar 180 days from it for the disclosure affidavit.
- In a § 145.682 case, start collecting expert signatures early. Each listed expert must sign. That is a scheduling problem, not a drafting problem.
- Docket any demand for an affidavit as a 60-day emergency. Under subdivision 6(a) of each statute, the demand is what starts the clock that ends in mandatory dismissal with prejudice.
- In a product case, calendar six months from the date the representation began under § 604.04, and send the notice in writing to everyone in the chain.
- Do not assume the same rules govern in every forum. Whether a state affidavit statute applies to a case filed in federal court is a distinct question of federal procedure, and this page does not address it.
Two adjacent Minnesota problems are worth reading with this one: the family of Minnesota deadlines that run from a fact rather than a docket entry, and Minnesota’s limitations periods and the exceptions that ruin people. If your defendant is an engineer or architect on a construction project, the contract itself may also contain clauses Minnesota voids outright — see Minnesota Voids Five Clauses in Your Construction Contract.
The observation
Screening statutes are usually defended on cost grounds: weak professional-liability claims are expensive to defend, and expensive to insure against, so the Legislature requires a plaintiff to show early that a qualified expert has looked at the case. That is a legislative judgment, and it is one the Legislature was entitled to make.
What is harder to defend is the triggering architecture. A rule that says “produce an expert affidavit within X days of filing” is a rule a competent lawyer can never miss, because the filing date is on the docket and the deadline can be calendared the same afternoon. Minnesota did not write that rule. It wrote one deadline that starts when an opposing party chooses to serve a demand, a second that starts when two lawyers hold a conference, and — in product cases — a third that starts on the day a client signed a retainer.
None of those are things a court records. All of them carry consequences that are described in the statute as mandatory.
The screening function does not require that. A statute can demand an expert affidavit and still hang the deadline on a date that exists in the file. That Minnesota’s do not is the reason these cases are lost on paper, by lawyers who had the expert and simply lost the race to a clock they could not see.
Madgett Law, LLC handles professional-liability and civil litigation in Minnesota state and federal court. If you are evaluating a claim against a licensed professional or a health care provider — or defending one — the affidavit questions are worth raising at the outset rather than after a motion. Send us a message or call 612-470-6529.
Sources: Minn. Stat. § 544.42 (actions against professionals; certification of expert review) — subd. 1 (definitions of “professional” and “action,” including the exclusion of claims requiring notice under § 604.04); subd. 2 (the two affidavits, service with the pleadings and within 180 days of commencement of discovery under Minn. R. Civ. P. 26.04(a)); subd. 3(a)–(c) (contents of the affidavit of expert review; the limitations exception and the 90-day period after service of the summons and complaint; and the good-cause waiver or modification application served with commencement, together with the scheduling-order provision and the 60-day/180-day sentence following denial); subd. 4(a)–(b) (identification of experts; attorney signature; interrogatory answers; extensions by agreement or for good cause); subd. 5 (pro se parties); subd. 6(a)–(c) (mandatory dismissal with prejudice; the 60-day-after-demand trigger; and the notice-plus-60-day cure with specific findings for deficiencies in the disclosure affidavit); subd. 7 (certification; attorney’s fees, costs, disbursements, and other damages). Minn. Stat. § 145.682 (certification of expert review; affidavit) — subd. 1 (definition of “health care provider,” incorporating § 145.61, subds. 2 and 4); subd. 2 (the two affidavits); subd. 3 (affidavit of expert review; the limitations exception and 90-day period); subd. 4(a)–(c) (identification of experts; signature by each listed expert and by the plaintiff’s attorney; extensions; and the medical malpractice scheduling and additional-expert provisions); subd. 5 (pro se plaintiffs); subd. 6(a)–(c) (mandatory dismissal with prejudice; the 60-day-after-demand trigger; and the requirements that the motion identify claimed deficiencies, that hearing be at least 45 days from service, and that no corrected filing be served before the hearing); subd. 7 (certification; attorney fees, costs, and disbursements). Minn. Stat. § 145.61, subds. 2 and 4 (definitions of “professional” and “health care”). Minn. Stat. § 604.04, subds. 1 and 3 (notice of possible claim; six months from the date of entering into an attorney-client relation; actual-notice sufficiency; duty to furnish the chain of manufacture and distribution; and the damages, costs, and attorney fees remedy, with the proviso that failure to give notice does not affect the validity of a claim against a party who did not receive notice). Minn. R. Civ. P. 26.04(a) (timing of discovery; parties may not seek discovery before conferring and preparing a discovery plan under Rule 26.06(c)). All from the Minnesota Office of the Revisor of Statutes, 2025 Minnesota Statutes and the Minnesota Rules of Civil Procedure as published by the Revisor. Currency check: the Revisor’s Table 2 shows the most recent entries for § 544.42 and § 145.682 as the 2014 Regular Session (ch. 153), no entries for § 604.04, and no 2025 or 2026 session entries for any section relied on here.
This article is general legal information about Minnesota law, not legal advice, and reading it does not create an attorney–client relationship. Whether an affidavit is required in a particular case, when it is due, and what happens if it is late depend on the claim, the defendant, the record, and the forum. Do not use this article to compute a deadline in your own matter. No outcome is promised or implied.