Last month we published a thought piece, Medical Monitoring and the Limits to Equity, pointing out how no-injury medical monitoring claims asserted in federal court could well fall outside the foundational limits on those courts’ equitable powers, given the holding in Grupo Mexicano de Desarrollo S.A. v. Alliance Bond Fund, Inc., 527 U.S. 308 (1999), limiting federal equity powers to the “the jurisdiction in equity exercised . . . in England at the time of the adoption of the Constitution and the enactment of the original Judiciary Act,” that being, of course, 1789. Id. at 318. We also concluded that the Judicial Act’s limits to federal equitable powers likely applied in diversity cases, given, Guaranty Trust Co. v. York, 326 U.S. 99, 104-06 (1945), and its progeny.
We cautioned, however, “that this argument seems never to have been tried before in the medical monitoring context,” given that we found no “opinion in any court citing to either Grupo Mexicano or Guaranty Trust that also included the phrase ‘medical monitoring.’”
That’s no longer true.
In Bio-Lab, Inc. v. Tartt, ___ S.E.2d ____, 2026 WL 2395789 (Ga. Aug. 18, 2026) – decided less than two weeks after our post – the Georgia Supreme Court came to the same result as the second part of our analysis – that the limits of equitable jurisdiction exercised by federal courts in diversity cases are federal in nature, given the Guaranty Trust line of cases. Id. at *5-6. Bio-Lab involved a medical monitoring claim, the state high court having accepted certified questions from a federal district court:
The Defendants moved to dismiss that request for equitable relief, arguing that, under Georgia law, the requested remedy is unavailable in the absence of allegations of present physical injury. . . . [G]iven the dearth of Georgia case law on medical monitoring in connection with mass torts, [the federal court] was “left with considerable uncertainty as to whether Georgia law permits medical monitoring as a tort remedy absent a current physical injury.”
Discerning no clear answer to that question, the district court opted to seek our input and certified the following questions to this Court:
(1) Under Georgia law, can a plaintiff exposed to toxic substances which may cause future disease obtain equitable relief in the form of medical monitoring costs absent an allegation of present physical injury; and
(2) If so, what standard must the plaintiff meet to obtain such relief?
Id. at *2 (emphasis added).
The Georgia Supreme Court interpreted the first question “as implicating two broader legal issues with relevance beyond the specific facts,” the first being “under what circumstances is equitable relief available.” Id. at *3. That was a question governed by state law. Id. To be entitled to equitable relief, a plaintiff “must first identify some legally cognizable ‘wrong’ or ‘injury’ that needs to be remedied.” Id. (citation and quotation marks omitted). That is a “separate question whether that plaintiff is entitled to some form of relief.” Id.
Bare fears of injury will not authorize equitable relief. Rather, where a plaintiff seeks an equitable remedy for a threatened legal injury, that injury must be imminent, not remote, before equitable relief is authorized.
Id. at *4 (citations omitted). Because “equity follows law,” equitable relief cannot be afforded “contrary to the law.” Id. (citation and quotation marks omitted).
Given the pleadings-based status of the case, the Tartt court refused to go any further, and did not directly address medical monitoring.
[R]esolving the issue of whether equitable relief is available will first involve a thorough and intensive evaluation of whether the Plaintiffs’ complaint includes sufficient factual allegations to demonstrate both a legally cognizable injury and the necessity of equitable relief to remedy that injury. But this Court, when answering questions certified to us by a federal court, does not reach the merits of the underlying case; instead, we answer the questions posed to us only in a general sense. . . . Thus, we respectfully decline to answer the district court’s questions to the extent that it calls on us to decide the ultimate issues raised by the Defendants’ motion to dismiss.
Id. (citation and quotation marks omitted).
If the court had stopped there, Tartt would have been a non-event, since it did not reach the issue of whether no-injury medical monitoring was an available equitable remedy under Georgia law.
What made Tartt bloggable was the court’s treatment of the second question – “when equitable relief is available, what is the appropriate form and scope of that relief?” Id. at *5. That question, Tartt recognized, was “largely” a federal question under Guaranty Trust:
Unlike the question of entitlement to equitable relief (something we agree with the district court that state law governs), the form of equitable relief that a federal court sitting in diversity may grant may (we believe) be largely a question of federal law. [citing Guaranty Trust and progeny decisions] We acknowledge that this is a surprisingly thorny issue. But we think the best reading of the relevant decisional law − which is not exactly a beacon of clarity − is that the appropriate form and scope of equitable relief must be determined as a matter of federal law.
Id. (other citations omitted) (emphasis added). Why? “[S]tate law clearly cannot commit the federal courts to grant equitable relief [in a diversity case] contrary to restraints imposed by the Constitution or an Act of Congress.” Id. (Wright & Miller citation omitted). “[C]rucially, some have interpreted Guaranty Trust to mean that state law does not govern the scope of the equity powers of the federal court, even when state law supplies the rule of decision.” Id. at *6 (citation and quotation marks omitted) (emphasis original).
The referenced “some” cases include those that we had collected in the Guaranty Trust portion of our post not two weeks earlier. Don’t worry, we’re not getting too full of ourselves – Tartt did not cite the same actual cases we did; ours were considerably more recent, so there’s no reason to believe that anybody involved in Tartt had ever read our post.
But, as to the second issue in our post, that federal law governed the scope of available equitable relief in diversity cases, Tartt reached the same conclusion we did:
So − as we understand the current state of the admittedly ambiguous law − a federal court, although limited by state jurisprudence on the question of whether the injunction remedy may be granted, is free to decide for itself what the scope and content of that injunction should be as befits the historically discretionary character of equity jurisprudence. State law provides the basis for relief; it does not necessarily constrain the scope of that relief. And that seems especially true where, as here, state law supplies no clear answer as to the availability of a specific form of injunctive relief.
2026 WL 2395789, at *6 (citation and quotation marks omitted). Tartt thus “declined to opine” on the availability of any “specific form of equitable relief,” such as medical monitoring. Id. at *7 (“We therefore respectfully decline to address whether Plaintiffs are entitled to a medical monitoring injunction.”). Before that could happen, the federal court hearing the case would have to “determine[] that equitable relief is appropriate (or properly asserted).” Id.
And that brings us back to the first, and most intriguing, point of our prior “Limits to Equity” blogpost – that “equitable” medical monitoring claims in federal court are subject to the United States Supreme Court’s Grupo Mexicano holding that federal equitable relief is limited to those powers recognized by the English courts of equity back in 1789. We have no reason to believe that any English chancellor in equity during the reign of King George III (or before) had permitted uninjured persons to recover for medical testing expenses based on mere exposure to a purportedly toxic substance. That’s something that we hope that the defendants in Tartt (and defendants in any medical monitoring litigation in federal court) will raise as a defense in the future.