Apple ordered to pay $184 million more in Masimo patent case, total reaches $818 million

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Judge James Selna ordered Apple to pay an extra $184 million in prejudgment interest, raising the Masimo patent case total to about $818 million.

The court turned down Apple's claim that interest would be a windfall and also denied Masimo's request for a 7 per cent rate, using Masimo's own borrowing cost instead.

Because the patent expired in June 2022, the award covers only past Apple Watch sales and does not affect current models.

A federal judge has added $184 million in prejudgment interest to the $634 million damages award Masimo won against Apple last year, lifting the total to roughly $818 million.

U.S. District Judge James Selna ruled that interest is required to make the patent holder whole, dismissing Apple’s contention that it would constitute a windfall. He also declined Masimo’s push for a 7 per cent rate — which would have yielded about $243 million — and instead applied Masimo’s actual borrowing rate compounded annually, according to coverage from MacRumors, 9to5Mac, and AppleInsider. “Interest from the time that the royalty payments would have been received merely serves to make the patent owner whole,” Selna wrote.

The underlying verdict, first reported by Reuters, came in November 2025 when a jury found Apple infringed a Masimo patent covering low-power pulse oximetry in the Apple Watch. That patent expired in June 2022, so the judgment applies only to historical sales. Apple disabled blood-oxygen readings on U.S. models after an International Trade Commission ban and later rolled out a redesigned version of the feature.

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