Apple's Watch Stays Banned: The Federal Circuit Affirms the Masimo Section 337 Exclusion Order

In Apple Inc. v. International Trade Commission, No. 2024-1285 (Fed. Cir. Mar. 19, 2026), the United States Court of Appeals for the Federal Circuit affirmed the U.S. International Trade Commission’s determination that certain Apple Watch models violate Section 337 of the Tariff Act of 1930 by infringing patents owned by Masimo Corporation and its affiliate Cercacor Laboratories. The decision, authored by Judge Stark, leaves in place the limited exclusion order and cease-and-desist order that the Commission issued on October 26, 2023, in Certain Light-Based Physiological Measurement Devices and Components Thereof, Inv. No. 337-TA-1276. Those orders took effect after the 60-day presidential review period, on December 26, 2023, and prompted Apple to disable the blood-oxygen feature on the Apple Watch Series 9 and Ultra 2 units it continued to sell in the United States. The appellate court’s affirmance confirms that the trade remedy survives Apple’s full menu of challenges to claim construction, validity, the domestic-industry requirement, and prosecution laches.

At a glance

• Forum and disposition: Federal Circuit affirmance of an ITC final determination; the import ban stands.
• Patents: U.S. Patent Nos. 10,912,502 and 10,945,648, directed to wearable light-based measurement of blood-oxygen saturation using optical emitters and photodetectors.
• Remedy: A limited exclusion order barring importation of infringing Apple Watch models, plus a cease-and-desist order against domestic sales of previously imported inventory.
• Headline holdings: The Commission may identify a domestic-industry article that pre-complaint prototypes represent, and may rest that finding on circumstantial evidence; it may also credit R&D investments in earlier non-practicing precursors that were “specifically tailored” to the patent-practicing article; Apple’s prosecution-laches defense fails.
• What it does not resolve: Whether Apple’s redesigned, iPhone-mediated blood-oxygen calculation falls outside the order. A separate ITC enforcement proceeding addressed that question, and the Commission declined review and terminated the matter on April 17, 2026.

Section 337 and the architecture of an exclusion order

Section 337 of the Tariff Act, codified at 19 U.S.C. § 1337, makes it unlawful to import articles that infringe a valid and enforceable U.S. patent, but only where a domestic industry “relating to the articles protected by the patent” exists or is in the process of being established. The statute is not an ordinary damages regime. The Commission does not award money; its principal weapons are the exclusion order, enforced at the border by U.S. Customs and Border Protection, and the cease-and-desist order, which reaches inventory already inside the country. That structure makes the ITC an unusually potent venue for a patentee whose adversary depends on a global supply chain. Apple, which assembles its watches abroad, plainly does.

The Masimo investigation followed the canonical path. Masimo filed its complaint in June 2021. An administrative law judge issued an initial determination in January 2023 finding a Section 337 violation as to claims of the asserted patents, and the full Commission issued its final determination on October 26, 2023, affirming the violation in part while modifying several subsidiary findings. The remedy was a limited exclusion order (“limited” because it reaches only the named respondent’s infringing articles rather than all infringing goods from any source), coupled with a cease-and-desist order. Apple’s appeal placed the entire edifice before the Federal Circuit, and the court’s affirmance means the orders continue to operate.

What gives the case its broader importance is not the existence of the remedy but the durability of its foundation. Apple did not merely contest infringement; it attacked the predicate that Masimo had a qualifying domestic industry at all, and it raised an equitable defense, prosecution laches, that has rarely succeeded but periodically resurfaces as a tool against patentees accused of strategic claim-drafting. The Federal Circuit rejected each line of attack, and in doing so clarified two recurring questions about the domestic-industry requirement.

The domestic-industry requirement: prototypes and prior iterations

Section 337’s domestic-industry requirement has two components. The “technical prong” asks whether the complainant’s own articles actually practice the asserted patent. The “economic prong” asks whether the complainant has made qualifying domestic investment (in plant and equipment, labor and capital, or engineering and research and development) with respect to those articles. Apple challenged both, and lost on both.

On the technical prong, Apple argued that the analysis had to be confined to the specific physical units Masimo produced in discovery, that Masimo had failed to show a single pre-complaint item practicing the asserted claims, and that the Commission had therefore rested on a “hypothetical” article. The Federal Circuit disagreed on each point. It held that the Commission permissibly treated the Masimo Watch as the domestic-industry article and reasonably viewed the RevA, RevD, and RevE prototype units, manufactured and tested before the complaint was filed, as physical articles practicing the asserted claims. It also rejected the premise that direct evidence was required, invoking its statement in Medtronic, Inc. v. Teleflex Innovations S.A.R.L., 70 F.4th 1331, 1337 (Fed. Cir. 2023), that circumstantial evidence is evidence and is not second-class to direct evidence, and noting that the Administrative Procedure Act permits an agency to receive any oral or documentary evidence. See 5 U.S.C. § 556(d). That reasoning matters well beyond wearables. Complainants in fast-moving technology fields frequently litigate before a polished commercial product exists, or where the patented features live in development hardware rather than a single shipping SKU. The court’s recognition that pre-complaint prototypes can represent the domestic-industry article, and that their patent-practicing character can be proven circumstantially, gives such complainants room to establish a domestic industry on the strength of their engineering record.

The economic prong produced the opinion’s most consequential reasoning. Apple argued that Masimo could not count investments poured into two earlier components, the Circle Sensor and the Wings Sensor, that did not themselves practice the asserted claims. The Federal Circuit held that the ITC may credit such investments, drawing the governing standard from Motorola Mobility, LLC v. International Trade Commission, 737 F.3d 1345, 1351 (Fed. Cir. 2013): nothing in Section 337 precludes reliance on investments “directed to significant components, specifically tailored for use in an article protected by the patent.” Predecessor investments qualify, the court explained, only where there is a sufficient nexus between the earlier investment and the protected article, such that the investment can fairly be said to have been made “with respect to” that article. Investments that would have been made independently of the patented article do not count. On this record, substantial evidence showed that the Circle and Wings work was part of the same iterative design process that produced the patent-practicing watch, and that those investments led to specifically tailored, significant technical features of the RevA and RevD variants. This is a meaningful clarification of how far upstream the economic prong reaches. R&D rarely proceeds in a straight line from concept to a single patent-practicing product; it proceeds through generations of non-practicing prototypes. By allowing the Commission to credit that earlier, foundational spend, the court aligns the domestic-industry analysis with the realities of iterative engineering, and makes it harder for respondents to slice a complainant’s investment history into disqualifying pieces.

Prosecution laches and the limits of an equitable escape hatch

Apple’s most aggressive defense was prosecution laches: the doctrine under which a patent may be rendered unenforceable when it issues only after, in the words of Symbol Technologies, Inc. v. Lemelson Medical, Education & Research Foundation, 422 F.3d 1378, 1385 (Fed. Cir. 2005), “an unreasonable and unexplained delay in prosecution.” Apple argued that Masimo sat on its rights for twelve years, from its 2008 provisional applications to the September 2020 filings that led to the asserted claims. The administrative law judge found that interlude was not a delay at all, crediting testimony of “continuous prosecution activity” during that period and of a “continuous unbroken chain of patent prosecution,” and observing that laches “should be applied only in egregious cases of misuse of the statutory patent system.” She also found no evidence that the newly asserted limitations were drawn specifically to cover Apple’s products.

The Federal Circuit reviews the applicability of prosecution laches for abuse of discretion. Assuming without deciding that Apple had preserved the argument, the court held that Apple failed to show any abuse of discretion: it was reasonable for the judge to conclude that Apple had not carried its burden to prove unreasonable and unexplained delay, and there was no record evidence that Masimo timed its prosecution to cover Apple’s products. The defense therefore failed.

The result is a useful reminder of the asymmetry built into prosecution laches. The doctrine demands proof of unreasonable and unexplained delay, and continuous, documented prosecution activity is largely fatal to that element. For accused infringers, the lesson is that laches is not a general-purpose tool for attacking older patents whose claims happen to read on a later-arriving product; it requires the kind of gamesmanship the record here did not show.

Open questions

The affirmance settles the validity and infringement of the asserted claims and the legitimacy of the remedy, but it leaves the most commercially significant question to a different track. The exclusion order reaches “infringing” Apple Watch models. Apple responded to the original orders by redesigning its product so that the blood-oxygen value is computed on a paired iPhone rather than on the watch itself. Whether that redesign escapes the order is not a question the Federal Circuit decided. An ITC administrative law judge addressed the redesign in a separate enforcement proceeding, issuing an enforcement initial determination on March 18, 2026, concluding that the iPhone-mediated approach does not infringe: one day before the Federal Circuit’s affirmance issued. The Commission declined to review that determination and terminated the enforcement proceeding on April 17, 2026, leaving Masimo free to appeal. The juxtaposition is striking: the patentee won the appeal that validated its patents and remedy on the same week the accused infringer effectively neutralized that remedy through redesign.

A second open question is doctrinal reach. The “specifically tailored” and “sufficient nexus” formulations for crediting predecessor investment will require line-drawing in future investigations. How attenuated can the connection be between a non-practicing precursor’s R&D and the eventual patent-practicing product before the investment no longer counts? The opinion supplies a direction but not a bright line.

Implications

• The ITC remains the venue of choice for patentees facing import-dependent rivals. A border remedy that money cannot fully substitute for retains its leverage even against the largest manufacturers.
• Domestic industry just got easier to prove for iterative developers. Pre-complaint prototypes can serve as the patent-practicing article, provable circumstantially, and foundational R&D in non-practicing predecessors can count toward the economic prong where it was specifically tailored to that article.
• Prosecution laches remains a narrow defense. Continuous prosecution activity will usually defeat it; accused infringers should not over-invest in the theory absent evidence of timing abuse.
• Design-arounds, not appeals, may be the decisive battleground. Apple’s redesign, moving a feature off the excluded article, illustrates that the most effective response to a Section 337 order can be engineering rather than litigation.
• Feature-level exclusion has a feature-level cure. When a remedy targets a discrete capability, relocating that capability can take a product outside the order’s scope, as the parallel ITC proceeding suggests.

Frequently asked questions

Does this decision mean the Apple Watch is banned in the United States? It means the import ban on the infringing models stands. Apple long ago adjusted its U.S.-sold watches (first by disabling the blood-oxygen feature, later by moving the calculation to a paired iPhone), so the practical effect on what consumers can buy is shaped more by those design changes and the separate redesign proceeding than by the affirmance itself.

Why did Apple lose at the ITC when it has prevailed in other patent disputes? The ITC applies Section 337, which couples ordinary patent infringement analysis with the domestic-industry requirement and offers exclusion rather than damages. Apple’s challenges to claim construction, validity, domestic industry, and prosecution laches each failed on the record, and the Federal Circuit reviews the Commission’s factual findings deferentially for substantial evidence.

What is the significance of crediting investment in earlier, non-practicing components? It clarifies how the economic prong of the domestic-industry requirement can be satisfied. A complainant need not show that every dollar of qualifying investment went into a product that itself practices the patent. Investment in earlier, non-practicing development can count where it was directed to significant components specifically tailored for use in the patent-practicing article, so that a sufficient nexus ties the spending to that article. Investment that would have been made regardless of the patented article does not count.

Authorities and sources

• Apple Inc. v. International Trade Commission, No. 2024-1285 (Fed. Cir. Mar. 19, 2026) (opinion): https://www.cafc.uscourts.gov/opinions-orders/24-1285.OPINION.3-19-2026_2663002.pdf
• Mintz, “Federal Circuit Affirms ITC Exclusion Order Against Apple Watch One Day After ITC Judge Approves Design-Around” (Mar. 27, 2026): https://www.mintz.com/insights-center/viewpoints/2231/2026-03-27-federal-circuit-affirms-itc-exclusion-order-against
• IPWatchdog, “Federal Circuit Affirms ITC Finding That Apple Watch Infringes Masimo Blood Oxygen Patents” (Mar. 23, 2026): https://ipwatchdog.com/2026/03/23/federal-circuit-affirms-itc-finding-apple-watch-infringes-masimo-blood-oxygen-patents/
• 9to5Mac, “Apple wins latest round in Masimo fight as ITC closes Apple Watch import ban case” (Apr. 17, 2026): https://9to5mac.com/2026/04/17/apple-wins-latest-round-in-masimo-fight-as-itc-closes-apple-watch-import-ban-case/
• Section 337 of the Tariff Act of 1930, 19 U.S.C. § 1337.