Apple Masimo – Apple faces a ballooning $818 million total bill after a federal judge ordered an additional $184 million interest payment in its ongoing patent battle with Masimo.
The bill for Apple’s patent infringement has grown by another $184 million. While the company was already facing a $634 million fine handed down in November 2025, the addition of interest payments pushes the total financial penalty to $818 million.
Federal Judge James Selina issued the ruling on October 5. dismissing Apple’s argument that the added interest would grant Masimo an unfair windfall. Drawing on U.S. Supreme Court guidance. the court determined that the interest from the period when royalty payments were originally expected simply serves to make the patent holder whole. For Apple. the decision ends a bid to lower the final cost. though the company avoided an even higher penalty: the judge rejected Masimo’s request for a 7% interest rate. opting instead to calculate the sum based on Masimo’s own compounding borrowing rate. Had the court sided with Masimo’s calculation. Apple would have owed an additional $59 million. bringing that interest total to $243 million.
The initial $634 million award, decided by a federal jury, stemmed from findings that Apple Watch heart rate notification features and workout modes violated Masimo’s patents. This figure sat at the low end of what Masimo requested but dwarfs Apple’s own estimates of $3 million to $6 million.
This outcome is the latest chapter in a legal saga that began in 2020. when Masimo first accused Apple of infringing 10 patents and stealing trade secrets by poaching key staff. The conflict escalated in 2021 with further lawsuits targeting blood oxygen technology in the Apple Watch Series 6. By late 2023. the dispute reached a breaking point. forcing Apple to prepare to halt watch sales to comply with an ITC ruling. A temporary stay on December 27. 2023. offered a reprieve. allowing Apple to bypass the ban by stripping blood oxygen sensing features from its code—a function that returned to U.S. devices 18 months later.
Since that time, the legal ground has shifted repeatedly. In April 2026, a U.S. District Court dismissed with prejudice Masimo’s complaint regarding the USITC’s decision to deny a reinstatement of the sales ban. By July 2026. Apple’s attempt to appeal the original $634 million jury award was rejected. cementing the payout that has now grown significantly under the judge’s latest interest order.
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