Apple Ordered to Pay Masimo $184 Million in Interest on Apple Watch Patent Damages

By Haedar

Photo: qimono / Pixabay

A patent damages award is not always the final number. According to a report by MedTech Dive, a judge of the U.S. District Court for the Central District of California has ruled that Apple must pay Masimo $184.2 million in prejudgment interest on the $634 million that a jury awarded last year for infringement of a Masimo pulse-oximetry patent by the Apple Watch.

The ruling, issued on a Monday in early October 2026, brings the total Apple has been ordered to pay to about $818.5 million. Masimo was acquired by Danaher for $9.9 billion in June, according to the same report.

Why interest was awarded

The U.S. standard for patent damages aims to put the patent owner in the position it would have been in had the infringer taken a reasonable royalty licence when infringement began. Masimo argued that because the jury's award was built on a per-watch running royalty negotiated as of that earlier date, interest was needed to make it whole. Apple argued the opposite: that the verdict was already large enough and that adding interest would be a windfall. As reported, the judge was not persuaded by Apple's position.

How the rate was chosen

District courts have discretion over the interest rate. Masimo asked for the 7% rate set by the California Constitution, which would have produced about $242.7 million. Apple proposed a rate that would have produced about $114.5 million. The court instead adopted Masimo's borrowing cost, compounded annually, a figure that Apple's own expert had also calculated, giving $184.2 million. Apple must also pay 4% post-judgment interest on the full $818.5 million from 20 July until the judgment is paid, a point Apple did not contest, according to MedTech Dive.

What it means for rights holders and Indonesia

The case shows how much time can add to a patent judgment: in this dispute, interest represents almost 30% of the original verdict. For companies weighing settlement against trial, the cost of delay belongs in the calculation from the start.

Indonesian patent law works differently. Under Law No. 13 of 2016 on Patents, compensation claims are brought before the Commercial Court, and there is no jury. We are not aware of an Indonesian court decision that has applied a comparable prejudgment-interest framework to patent damages, so foreign patent owners should not assume U.S.-style figures will carry over. Documenting losses and licensing benchmarks early remains the most practical step in any jurisdiction.

Sources

• MedTech Dive, "Apple ordered to pay Masimo $184M in interest on patent damages" (7 October 2026)