The Pulse July 2025 - Affidavit of Merit in Malpractice Cases Filed in Missouri

Richard Hunsaker and Caleb Harmon

Many states have statutory requirements to ensure that legal actions initiated against medical providers have been “certified” by an appropriate medical professional as having merit. The nuances from state to state are significant and warrant close scrutiny.

In Missouri, the requirements are governed by RSMo 538.225.

538.225 requires the following:

The plaintiff shall file an affidavit with the court stating that he or she has obtained the written opinion of a legally qualified health care provider, which states that the defendant health care provider failed to use such care as a reasonably prudent and careful health care provider would have under similar circumstances and that such failure to use such reasonable care directly caused or directly contributed to cause the damages claimed in the petition.
The term “legally qualified health care provider” shall mean a health care provider licensed in this state or any other state in the same profession as the defendant and either actively practicing or within five years of retirement from actively practicing substantially the same specialty as the defendant.
The affidavit shall state the name, address, and qualifications of such healthcare providers to offer such an opinion.
A separate affidavit shall be filed for each defendant named in the petition.
The affidavit shall be filed no later than ninety days after the filing of the petition unless the court, for good cause shown, orders that such time be extended for a period of time not to exceed an additional ninety days.
If the plaintiff fails to file such an affidavit, the court shall, upon motion of any party, dismiss the action against such moving party without prejudice.
Within one hundred eighty days after the filing of the petition, any defendant may file a motion to have the court examine in camera the aforesaid opinion, and if the court determines that the opinion fails to meet the requirements of this section, then the court shall conduct a hearing within thirty days to determine whether there is probable cause to believe that one or more qualified and competent health care providers will testify that the plaintiff was injured due to medical negligence by a defendant. If the court finds that there is no such probable cause, the court shall dismiss the petition and hold the plaintiff responsible for the payment of the defendant’s reasonable attorney fees and costs.

Compared to Illinois, Missouri’s requirements for a Certificate of Merit have more teeth. However, there are significant differences which must be considered by the defense attorney. Notably, 538.335 does not require sharing the affidavit with defense counsel. 538.225 requires filing the affidavit with the court and, if the defendant chooses, a later request that the court conduct an in-camera inspection to assess whether the affiant or affiants will attest that “the defendant health care provider failed to use such care as a reasonably prudent and careful health care provider would have under similar circumstances and that such failure to use such reasonable care directly caused or directly contributed to cause the damages claimed in the petition.” Illinois, by way of contrast, requires that the affiant set forth there is a reasonable and meritorious cause for bringing the action – a much lower standard.

To no one’s surprise, 538.225 has been challenged on numerous occasions by the plaintiff’s bar.

In Hink vs.Helfrich, 545 S.W. 3d 335 (Mo. en banc 2018), the Missouri Supreme Court upheld the constitutional validity of the health care affidavit requirement for medical negligence actions. In doing so, the court strictly construed the mandatory statutory language, holding that the plaintiff’s medical malpractice case was properly dismissed for failure to file the required affidavit. In her Petition, the plaintiff challenged the constitutionality of this statute, as revised in 2005, arguing that it violated a plaintiff’s right to a jury trial, the state’s open courts provision, and the separation of powers. When the plaintiff failed to file any affidavit within the prescribed time limit, the defendant physician filed a Motion to Dismiss. The trial court granted the defendant’s Motion, and the plaintiff appealed. The Missouri Supreme Court affirmed the dismissal.

In Hink, the Court endorsed its prior holding in Mahoney v. Doerhoff Surgical Services, Inc., 807 S.W.2d 503 (Mo. en banc 1991), holding that the affidavit requirement does not violate the constitutional right of access to the courts under the Missouri Constitution, Article I, § 14, because access to the courts simply means “the right to pursue in the courts the causes of action the substantive law recognizes.” The Court further explained that Section 538.255’s affidavit requirement is consistent with this substantive law because the legislative purpose of requiring an “affidavit of merit” is to prevent frivolous medical malpractice lawsuits, particularly where a plaintiff cannot put forth adequate expert testimony to support her claims. The court concluded that the requirement does not deny a fundamental right, or free access to the courts, and does not delay the pursuit of the cause in the courts. At most, it merely redesigns the framework of the substantive law to accomplish a rational legislative end of protecting the public and litigants from the cost of ungrounded medical malpractice claims. The Court also rejected the argument that Section 538.255’s affidavit requirement violates the right to trial by jury because the statute simply reiterates existing requirements on plaintiffs: it does nothing more than “parallel” the requirement of Missouri Rule 55.03, that an attorney exercise a reasonable inquiry to ensure the suit is well grounded in fact and law. The Court noted that the affidavit of merit does nothing more than provide more specific guidance as to how medical malpractice plaintiffs must comply with existing pre-suit requirements rather than imposing any new requirement or other restrictions on his or her right to seek redress.

Significantly, the initial version of 538.255 gave the trial court discretion on whether to dismiss where an affidavit was not filed within 90 days. In 2005, the statute was amended to provide that the court “shall” dismiss the action if an affidavit is not filed. This amendment took away the trial court’s discretion where no affidavit was filed within the statute’s time parameters.

The Hink court also rejected the plaintiff’s contention that the 2005 amendment to Section 538.255 outlining “legally qualified healthcare providers” to be only those who practice in “substantially the same specialty” as the defendant, impermissibly imposes a stricter burden on the plaintiff than is required to prove a prima facie case of negligence at trial. Because Hink failed to file any affidavit, the Court held that she was not affected by the alleged deficits to Section 538.255, and therefore lacked standing to challenge its constitutionality. Notably, the Court observed that its interpretation of “substantially the same specialty” includes persons qualified by expertise rather than board certification, and that Section 538.255 does not require the affidavit to rely on only a single expert opinion for both breach of the standard of care and causation.

In 2022, the Missouri Supreme Court had the opportunity to revisit another challenge to Section 538.255. In Giudicy v. Mercy Hospitals East Communities, 645 S.W.3d 492 (Mo. en banc), the Court dealt with a case where the initial action was voluntarily dismissed and refiled. The 180-day deadline in which to submit the affidavit of merit was not met. Instead, the plaintiff’s counsel sought leave to file affidavits of merit 198 days after the refiling of the case.

The Court was presented with some additional arguments, including a “substantial compliance” claim along with a claim of waiver as the defendant did not specifically raise, as an affirmative defense, the failure to file a 538.225 affidavit. There were other arguments raised by the plaintiff, including constitutionality, separation of powers, retrospectivity, and clear title/single subject legislation violations. All of these arguments were rejected by the Missouri Supreme Court.

Conclusion

To be sure, the affidavit requirement could be stronger. For example, the Defendant is not entitled to a dismissal with prejudice in those cases where the affidavit requirement is not met. However, 538.255 sets out an important requirement on the Plaintiff, which must be met in every malpractice suit. Be aware of the requirements and the applicable deadlines. The first item of business is to confirm that the Plaintiff has filed the required affidavit with the Court. Often, if it is decided that a request for an in-camera inspection by the Court is warranted, the opposing lawyer will simply provide a copy of the affidavit to counsel to forego the process of conducting an in-camera inspection by the Court. If you are provided with a copy of the affidavit, this will be quite insightful as it will give you a head start on the expert opinion evaluation process. Unlike Illinois and other states, Missouri only requires the identification of the expert. Missouri does not require a full and complete outline of the expert’s anticipated opinions prior to the commencement of a deposition. Often, defense counsel will not have a complete understanding of the Plaintiff’s expert’s opinions until after a deposition is completed. Gaining early insight into the opposing expert’s theory of liability, causation, and damages can be very helpful. Remember, Missouri requires that the affiant set out the following: “that the defendant health care provider failed to use such care as a reasonably prudent and careful health care provider would have under similar circumstances and that such failure to use such reasonable care directly caused or directly contributed to cause the damages claimed in the petition.” This is the same standard that will be applied at the time of trial. Finally, it should be argued that if the disclosed expert was the same person who prepared the 538.255 affidavit, that affidavit must be produced at the time of the expert’s deposition. Scrutinizing that early filed affidavit can provide for useful cross examination in many cases.