Overview
The patent vs. trade secret choice is typically one that weighs disclosure and term of protection. Insulet Corp. v. EOFlow adds a different axis to that analysis: accrual. In this case, a jury found that EOFlow had misappropriated the trade secrets behind Insulet’s Omnipod wearable insulin pump and returned a nine-figure verdict. But the Federal Circuit reversed, holding that Insulet’s Defend Trade Secrets Act (“DTSA”) claims had accrued years before suit and were untimely. Judge Prost dissented. Insulet Corp. v. EOFlow, Co., No. 2025-1807 (Fed. Cir. May 28, 2026).
The decision warrants attention because it considers two different accrual clocks, the patent claim accrual clock and the trade secret claim accrual clock. Patent term is finite, but infringement accrues act-by-act with each new act opening its own six-year damages window under 35 U.S.C. § 286. This accrual structure, combined with the evolving “settled expectations” and discretionary denial considerations for inter partes review (IPR), can soften the impact of delayed enforcement: patentees may wait to bring suit because exposure to IPR now decreases the longer the patent has been in force.
By contrast, trade secret protection can last indefinitely, yet a continuing misappropriation is treated as a single claim. In other words, the first instance of a misappropriation of trade secrets that a diligent owner should have discovered starts a three-year clock running. This three-year clock will then continue to apply to the entire claim. This accrual structure encourages prompt filing.
Insulet compounds the effect by further compressing the three-year accrual window. First, Insulet tied accrual to when a reasonably diligent plaintiff knew or should have known enough to plead misappropriation, which could be satisfied by “access-plus-similarity.” Second, once triggered, that same three-year accrual period can encompass all related trade secret claims, even those uncovered later in discovery. In an era of faster, AI-enhanced competitive intelligence, this framework sharpens the practical accrual window: the more closely a company monitors competitors, the harder it becomes to argue delayed discovery. The policy thus favors prompt, decisive action when a confidential relationship breaks down. The Insulet dissent cautioned that the majority’s approach may push plaintiffs to “race to the courthouse with undeveloped claims based on mere suspicion.” While the majority opinion undoubtedly encourages prompt filing, a more optimistic view may be that it also disciplines overbroad pleading: plaintiffs who rely on early, publicly observable similarities to plead sweeping “kitchen sink” claims risk pulling the accrual date backward—and time-barring stronger claims tied to later-discovered misappropriation.
Below is a breakdown of Insulet’s key decisions, including the dissent’s view and key takeaways.
I. Jurisdiction and Patent Claim Accrual
Although the appeal centers on trade secret claims, the Federal Circuit first confirmed its jurisdiction based on Insulet’s earlier patent claims, which were dismissed from the case. While dismissals “without prejudice” typically divest jurisdiction, dismissals with prejudice do not. Slip Op. at 7–9. Here, after winning at trial on its trade secret claims, Insulet amended its complaint to delete its patent claims, which the district court then dismissed “without prejudice.” The Federal Circuit held, however, that these claims were effectively dismissed “with prejudice” because at least some of them were time-barred under 35 U.S.C. § 286, which bars recovery barred for acts occurring more than six years before suit. Slip Op. at 7–9. Although Insulet argued § 286 is merely a damages limitation but does not technically bar bringing suit, the Federal Circuit explained “this is a distinction without a difference,” treating § 286 as a time bar. Id. at 8.
Takeaway: Although largely procedural, the jurisdictional ruling highlights two practical points for the rest of the opinion. First, Insulet’s reach regarding the below discussed trade secret claims is somewhat limited. As Insulet applied First Circuit law, it is not binding authority for every DTSA action, nor would the Federal Circuit be reviewing DTSA-only cases without other claims like patent claims that would confer jurisdiction. Instead, DTSA-only cases would be reviewed in regional circuits that could approach trade secret accrual differently from the Federal Circuit in Insulet., though Insulet is still likely to carry persuasive weight. As a result, plaintiffs facing limitations risk on trade secret claims and are in situations similar to those in Insulet may consider pursuing patent claims in a separate action to avoid Federal Circuit review on trade secret claims. Second, term and accrual for patents and trade secrets cut in opposite directions. Patents offer limited term but a forgiving, six-year, act-by-act accrual regime. When combined with PTAB doctrines like discretionary denial and settled expectations, this regime may modestly incentivize patent owners to delay suit, as IPR proceedings may be harder to defend within the first six years the patent is in force and easier after the first six years. Trade secrets, by contrast, can last indefinitely but have front-loaded limitations, where the earliest discoverable misappropriation can control the entire claim.
This tradeoff should factor into decisions about whether to pursue patent or trade secret protection.
II. Accrual of DTSA Claims
Applying First Circuit law, the Federal Circuit then turned to the timeliness of Insulet’s DTSA claims. While the Federal Circuit declined to decide which exact standard applies for triggering the DTSA statute of limitations, it nevertheless held that knowing sufficient facts for pleading trade secret claims under an “access-plus-similarity” framework can trigger the trade secret accrual clock, and further held that once that clock is triggered from one trade secret claim, it is triggered for all related claims against trade secret claims, even those uncovered later in discovery. The dissent challenged each of those determinations.
1. The Federal Circuit Declined To Decide The Test For What Triggers DTSA SOL
The statute of limitations for Insulet’s DTSA claims runs 3 years from when those claims were “discovered or by the exercise of reasonable diligence should have been discovered.” 18 U.S.C. § 1836(d).Unlike patent claims, “a continuing misappropriation constitutes a single claim of misappropriation” and not a new event that triggers a new limitations period. Id. In this case, the parties argued different triggers for the limitations period. EOFlow urged an “inquiry-notice” trigger, which is “when the first event occurs that would prompt a reasonable person to inquire into a possible injury,” while Insulet invoked the Merck discovery standard, which is when it “knew or should have known . . . the facts it needed to sufficiently plead a trade secret misappropriation claim.” See Merck & Co. v. Reynolds, 559 U.S. 633 (2010). The Federal Circuit declined to choose between the standards, reasoning that Insulet’s claims failed even under the stricter Merck standard. Slip Op. at 10. The dissent pushed back on this hedge, asserting that the plain language of § 1836(d) requires the Merck discovery standard and that practically, the majority’s approach collapses into inquiry-notice. Slip Op. at 2–3 (Prost, J., dissenting).
Takeaway: Given uncertainty over whether courts will frame accrual as inquiry-notice or discovery, and how practically they could collapse the two, plaintiffs should assume the clock starts early and err toward earlier filing (consistent with what the dissent predicts).
2. The Federal Circuit Applied UTSA’S “Access-Plus-Similarity” Framework To DTSA
Although the Federal Circuit did not formally decide whether Merck or inquiry-notice governs accrual, it applied UTSA’s “access-plus-similarity” framework to assess whether a DTSA claim is adequately pled and, by extension, to guide the analysis of when Insulet knew or should have known enough to satisfy Merck. Under that framework, misappropriation may be properly pled through allegations demonstrating defendant’s access to the trade secret (“access”) and its similarity to the defendant’s design (“similarity”). The dissent agreed with that framework but disputed the majority’s application.
a. Hiring employees who had prior access to trade secrets suffices to plead “access.”
The Federal Circuit explained that a defendant’s “access” to the trade secret can be pled by relying on circumstantial evidence, and its holding supports that such “access” could occur simply by hiring former employees of the plaintiff who had access to the trade secrets during their former employment.[1] The Federal Circuit determined that Insulet knew sufficient facts to plead “access” by March 2019 because its internal emails from around that time revealed that Insulet’s COE and VP knew that “the people running EOFLOW . . . and their designer . . . are past Insulet folks.” Slip Op. at 21 (cleaned up). Although discovery later revealed that a former Insulet employee had shared confidential documents with EOFlow, it was Insulet’s initial awareness of a former employee working for a competitor that set the date Insulet could have sufficiently pled the “access” prong. The dissent disagreed, criticizing reliance on “the mere fact that Insulet’s former employee had knowledge of and access to Insulet’s trade secrets and subsequently worked on” the accused device. Slip Op. at 7 (Prost, J., dissenting).
Takeaway: Under an “access-plus-similarity” theory, alleging that a former employee with relevant knowledge joined the defendant may suffice, but plaintiffs should plead additional facts suggesting misuse where possible, as other circuits may apply the framework differently. Plaintiffs might also track when employees depart for competitors, as those dates may trigger accrual.
b. Pleading visual similarities could establish “similarity” but may pull back accrual.
Three of the four trade secrets on appeal related to the design, manufacturing, and CAD files for Insulet’s wearable insulin patch pump, and the original complaint focused on visual design similarities to allege misappropriation. Opinion at 23, 30. The Federal Circuit held that Insulet was aware of those pleaded similarities when it viewed product samples at 2018 and 2019 conferences. Notably, the Federal Circuit’s “similarity” analysis rested on public-facing features that may not themselves be trade secrets, but the court declined to resolve whether those features qualified as trade secrets, emphasizing instead that its analysis turned on how Insulet pleaded its allegations in the original complaint. Slip Op. at 27, n. 9; Slip Op. at 20; See Slip Op. at 22–33. The court also rejected the argument that Insulet could not visually “see” the manufacturing process, reasoning that manufacturing was “only a portion of the” relevant trade secret and thus “Insulet could have discovered the similarity of the design . . before the critical date.” Slip Op. at 29–30. The dissent challenged the majority’s factfinding, noting the jury already weighed the evidence and resolved the statute of limitations issue in Insulet’s favor. Slip Op. at 8–13 (Prost, J., dissenting).
Takeaway: Plaintiffs should avoid anchoring similarity in publicly observable features, or at least ensure discovery of those similarities falls within the limitations window. Because Insulet ties accrual to what could have been alleged earlier, broad pleadings that could have been supported by earlier, publicly available information can backfire by pulling the clock backward and putting the entire claim at risk.
3. A Triggering Event For One Trade Secret Can Start the Accrual Clock For All Broadly “Related” Alleged Trade Secrets
Insulet’s fourth trade secret related to its occlusion-detection algorithm, which it added to the case during discovery. Unlike the other trade secrets, the Federal Circuit did not analyze access and similarity for the occlusion-detection algorithm. Instead, it held that when the statute of limitations begins to run on some of the trade secret claims, it runs on all related trade secret claims asserted against the same defendants. Slip Op. at 15–20. The dissent objected that this rule was neither raised by EOFlow nor established under First Circuit law, and noted that Insulet allegedly discovered the algorithm only through discovery, as it was not used in the final product. Slip Op. at 11–13 (Prost, J., dissenting). The majority defended its approach as necessary to ensure that the limitations period runs even “for trade secrets that do not outwardly manifest in a misappropriator’s product” because “otherwise, absent direct proof . . . the statute of limitations would never expire for a trade secret that could not be discovered based on publicly available information or other information known to the plaintiff.” Slip Op. at 18 (emphasis in original). That rationale sits uneasily with the nature of trade secrets, which typically do not outwardly manifest or are public facing; that is what makes them secret. Had Insulet asserted only the algorithm trade secret based on non-visual similarities, the claim might have been timely—though it likely would not have been discovered without the broader case.
Takeaway: Plaintiffs should avoid reflexively asserting every conceivable trade secret without fully understanding the accrual considerations for each one. Weaker, earlier-discovered claims can set the accrual date for stronger, later-discovered ones. In some cases, restraint at the pleading stage may preserve viability later.
Conclusion:
The familiar framework for choosing between patent and trade secret protection asks whether an innovation is better disclosed or better concealed, weighing detectability, reverse-engineerability, competitive lifespan, and potential term. Insulet suggests that accrual deserves closer attention in that analysis. Patents offer a fixed, forward-running clock and forgiving, act-by-act accrual, so the worst case may just be a trimmed damages tail, and doctrines like settled expectations at the PTAB may further soften the impact of any delay. Trade secrets offer potentially unlimited term, but a single, front-loaded enforcement clock tied to when a diligent owner could have first pleaded misappropriation. Whether the majority drew the diligence line in the right place is debatable, and the dissent observed that the standard demands reasonable, not “maximum feasible,” diligence. However that debate is resolved, Insulet forces parties to treat accrual not as a background litigation issue but as a front-end strategic constraint.
[1] The dissent challenged this, explaining that Insulet did not know that its former employees had continued that access when it changed employers. Slip Op. at 4–6. (Prost, J., dissenting).
