Apple's $634 Million Apple Watch Patent Bill Just Got Even Bigger

Apple's $634 million patent loss to medical technology firm Masimo has been significantly increased after a federal judge ordered the tech giant to pay an additional $184 million in interest, bringing the total to roughly $818 million. This ruling marks an escalation in the ongoing legal battle between the two companies. However, the figure does not include any interest that continues to accumulate until the judgment is paid off.

Judge James Selna dismissed Apple's claim that the prejudgment interest would be a windfall, citing Supreme Court guidance that it serves to put the patent owner back in the position they would have been in if royalty payments had been received during the infringement period. The court used Masimo's own borrowing rate, compounding annually from the start of the infringement, instead of the 7% rate requested by Masimo.

This dispute centers around Masimo's pulse-oximetry patent, and Apple has already redesigned its affected models. The patent issue was settled in November 2025, with a jury ruling that Apple's heart-rate features infringed Masimo's patent and awarding the company $634 million.