Knobbe Martens Guides Masimo to $634M Win Against Apple in Patent Infringement Case

Rhea-AI Summary

Masimo (NASDAQ: MASI) won a patent infringement verdict against Apple after an eight-day jury trial in the U.S. District Court for the Central District of California, with the jury awarding $634,313,913 in damages and finding infringement on all asserted claims.

The case is part of a long-running, multi-venue dispute between the companies; Knobbe Martens led Masimo's trial team and has secured other wins for Masimo, including an import ban on infringing Apple Watches at the U.S. International Trade Commission in early 2024.

Positive

• $634,313,913 jury damages award
• Jury found infringement on all asserted claims
• Prior ITC import ban on infringing Apple Watches (early 2024)

Negative

• Dispute remains ongoing in multiple venues

Insights

Intellectual property litigator

Jury found Apple infringed Masimo patents and awarded $634,313,913.

The verdict establishes that a jury concluded infringement on all asserted claims after an eight-day trial in the U.S. District Court for the Central District of California on Nov 18, 2025. The award of $634,313,913 is a concrete monetary remedy tied directly to the patent claims presented at trial. The case sits within a broader, multi-venue dispute between the parties that has produced prior enforcement outcomes, including an earlier import ban in a related proceeding.

Primary dependencies include the finality of the jury verdict and any post-trial motions or appeals that could alter damages or liability. The presence of co-counsel and prior wins in other forums shows sustained enforcement strategy, but appellate review remains an immediate procedural risk to the award. Watch for post-trial filings and appellate dockets over the next 6–24 months, as those steps will determine whether the judgment is affirmed, modified, or stayed.

IRVINE, Calif., Nov. 18, 2025 /PRNewswire/ -- A team from Knobbe Martens led medical device pioneer Masimo (NASDAQ: MASI) to a victory over Apple in a dispute involving Masimo's patented heart monitoring technology.

Following an eight-day jury trial in the U.S. District Court for the Central District of California, a jury returned a verdict of patent infringement on all claims asserted, and awarded Masimo $634,313,913 in damages. The win is just one of multiple wins by the Knobbe Martens team in a long-standing dispute between Masimo and Apple, proceeding in multiple venues. 

More information on the win may be found here.

Commenting on the case, Knobbe Martens partner Steve Jensen said, "This verdict validates Masimo's persistence in protecting its intellectual property on its life-saving technology. It has been an honor to represent Masimo throughout this case, and for the last 32 years, and to obtain a result that validates the company's commitment to advancing patient care through innovation."

The Knobbe Martens team is led by Mr. Jensen. The jury trial was led by Brian Horne, with Brian Claassen, Sheila Swaroop and Joseph Re as other trial presenters. The team further included Nicholas Zovko, Perry Oldham, Kendall Loebbaka, Douglas Wentzel, Adam Powell, Daniel Hughes, Mark Kachner, Ben Shiroma,Laura Liebman, Melis Tirhi, Isabella Pestana and Rhett Ramsey. Sullivan and Cromwell partner Dustin Guzior and special counsel Laurie Stempler served as co-counsel on the case.

The patent was also procured by Knobbe Martens lawyers Jarom Kesler and John Grover. And, it was defended in an inter partes review filed by Apple at the Patent Trial and Appeal Board by Mr. Kesler and Joshua Stowell.

Knobbe Martens has delivered a number of successes for Masimo in its ongoing dispute with Apple. In early 2024, in a case before the U.S. International Trade Commission, the firm secured an import ban on infringing Apple Watches. Last fall, Masimo also defeated Apple in its patent case against the current Masimo W1 health watch.

This is the latest in a series of recent successes for Knobbe Martens' industry-recognized patent litigation team, particularly on behalf of clients in the life sciences space. In September, a team from the firm led by Mr. Horne secured a noteworthy success on behalf of innovator Sigray, Inc. in an IP dispute involving groundbreaking x-ray technologies. Last month, the firm obtained a significant appellate victory for Edwards Lifesciences in a high-stakes patent infringement dispute involving prosthetic heart valve technology.

Learn more about the team's recent successes and accolades here.

About Knobbe Martens

Knobbe Martens protects the ideas that drive innovation and propel our world forward. As a leading intellectual property and technology law firm, clients worldwide rely on us to safeguard their products, brands, and technologies through strategic counsel and high-impact litigation. With offices across the U.S., our lawyers and technology specialists collaborate to deliver tailored solutions for clients ranging from multinational corporations to start-ups and emerging companies at every stage. Discover more at www.knobbe.com.

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SOURCE Knobbe Martens

FAQ

What did Masimo (MASI) win against Apple on November 18, 2025?

A jury found patent infringement and awarded Masimo $634,313,913 in damages.

How much did the jury award Masimo (MASI) in the November 2025 patent verdict?

The jury awarded Masimo $634,313,913 in damages.

Did the jury find infringement on all claims in the Masimo (MASI) v. Apple trial?

Yes, the jury returned a verdict of infringement on all claims asserted.

Who led Masimo's legal team in the November 2025 verdict against Apple?

A Knobbe Martens team led by partner Steve Jensen, with trial lead Brian Horne, led the case.

Has Masimo (MASI) had other legal wins versus Apple before this November 2025 verdict?

Yes; earlier wins include a U.S. ITC import ban on infringing Apple Watches in early 2024 and other favorable rulings.

Does the November 2025 verdict end the Masimo (MASI) dispute with Apple?

No; the companies remain engaged in a long-standing, multi-venue dispute according to the announcement.