Apple must pay an additional $184 million in interest on a $634 million patent verdict favoring Masimo, bringing the total obligation to about $818 million. Post-judgment interest can continue to accrue until the amount is paid.
According to Bloomberg Law’s report on the October 5 ruling, US District Judge James V. Selna rejected Apple’s argument that the added interest would give Masimo a windfall. The judge said the interest compensates the patent owner for royalty payments it did not receive during the infringement period.
The court did not grant everything Masimo requested. It declined to use a 7% rate that would have raised the interest portion to $243 million, instead applying Masimo’s borrowing rate with annual compounding.
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The verdict remains under appeal
A jury awarded Masimo $634 million in November 2025 after finding that Apple Watch heart-rate notifications and workout features infringed a patent. Apple later sought to overturn or reduce the result, but a federal judge left the verdict in place. MacObserver covered Apple’s failed challenge in July.
This case is separate from the International Trade Commission dispute that affected blood-oxygen functionality on Apple Watches sold in the United States. The patent involved in the $634 million verdict expired in 2022, so the ruling concerns historical sales rather than removing current heart-rate features.
Apple has said it plans to appeal the underlying verdict. The new interest order increases the amount at stake while that legal process continues.
Neither the interest order nor the appeal changes how owners use current Apple Watch health and workout features while the dispute proceeds.
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