A judge added $184 million in interest to Apple's Masimo patent bill

A federal judge has ordered Apple to pay Masimo another $184 million, this time in interest on the $634 million a jury awarded in November 2025, Bloomberg Law reported. That takes the bill to around $818 million, and post-judgment interest keeps accruing until Apple pays. Judge James Selna rejected Apple's argument that interest would hand Masimo a windfall, citing Supreme Court guidance that it only makes a patent owner whole for royalties it should have received. He had already upheld the verdict in July.

Masimo asked for a 7 percent rate, which would have put the interest at $243 million, and Selna instead used Masimo's own borrowing rate, compounded annually from when the infringement began, per MacRumors. The patent covers pulse oximetry and expired in June 2022, so the ruling is about past Apple Watch sales and doesn't touch the heart-rate features in current models. It's also separate from the Masimo dispute behind the US import ban on some Apple Watch models, after which Apple disabled blood oxygen on affected new watches and brought back a redesigned version in 2025.