Apple Switched Off Blood-Oxygen on the Apple Watch Rather Than License Masimo's Patents

By January 2024, Apple had readied a version of the Apple Watch Series 9 for the United States with a hole where a feature used to be. The blood-oxygen app, present on the same model sold everywhere else in the world, was set to disappear — switched off in software before the watch ever reached a wrist, once Apple's appeal ran out of road. Apple had not run out of sensors. It had run out of legal room. A U.S. import ban was closing in, and rather than pay to keep the feature, Apple chose to ship a deliberately lesser product.²

The tidy version of this story is that Apple lost, gave up the feature, and eventually paid Masimo hundreds of millions of dollars. Almost every beat of that is misleading. Apple did not abandon blood-oxygen sensing — it re-engineered it. And the widely quoted nine-figure verdict comes from a different courtroom, over a different patent, than the one that ever touched the import ban.

The real thesis is colder than capitulation. Faced with a fork — license the patents and pay a rival, or fight and route around it — Apple chose the second path at every step. Disable the feature, keep selling watches, appeal the order, redesign the technology, and litigate until the calendar and the engineering both bend your way. It is not the behavior of a company that lost. It is the behavior of a company that decided the one thing it would not do was write Masimo a licensing check.

The fork every infringing product faces: pay the toll, or build the detour — and Apple has almost never chosen the toll

The origin of the fight is more tangled than the theft narrative allows. Apple's dealings with Masimo trace back to 2013, when Apple sought Masimo's pulse-oximetry technology and internally floated acquiring the company, with founder Joe Kiani discussed as an executive. Tim Cook rejected the acquisition — Masimo's business sold to hospitals, not consumers — and Apple ended the talks within months, then recruited roughly 25 Masimo employees, including its chief medical officer and an executive slated to become its CTO.³ Kiani told the Senate Judiciary Committee that Apple hired 'over 20 of our team members' after he had shared Masimo's plans believing a partnership was forming.⁴

That backstory matters because it frames the decision Apple would face a decade later. In June 2021 Masimo took its case to the International Trade Commission, and the ITC eventually found that Apple Watch models — starting with the Series 6, launched in September 2020 — infringed Masimo patents covering optical blood-oxygen sensing, issuing an exclusion order that barred them from import.¹ Now the fork was live and unavoidable. An infringing product that a court has ordered off the shelves has two doors. Behind one: a license, negotiated with the rival, priced by the rival, paid indefinitely. Behind the other: an engineering detour and a war of attrition. Apple walked through the second door and locked the first.

Moving the math off the watch and onto the phone: the ban targeted a sensor doing a calculation — so Apple moved the calculation somewhere the ban didn't reach

The detour was not a marketing gesture. It was a genuine re-architecture. In August 2025, Apple re-enabled a redesigned Blood Oxygen feature for eligible U.S. watches through iOS 18.6.1 and watchOS 11.6.1. The trick was where the work happens: instead of the watch computing the blood-oxygen reading itself, the sensor data is shipped to the paired iPhone, which does the calculation and displays the result in the Health app's Respiratory section — a change U.S. Customs signed off on.⁷ The watch still gathers the light readings. It just no longer performs the specific patented act on the wrist.

This is the mechanism, and it is worth sitting with, because it explains why 'Apple gave up the feature' misses the whole play. Patent claims are precise; they cover a particular thing done in a particular place. The exclusion order rested on the watch performing optical blood-oxygen sensing. Move the calculation off the watch, and you have arguably stepped outside the fence without stepping outside the neighborhood. In March 2026, an ITC administrative law judge validated exactly that reading, finding 'no underlying act of direct infringement' in the redesigned, iPhone-dependent feature — while on the very same day the Federal Circuit affirmed the original 2023 exclusion order, leaving only the old on-watch version banned.⁸ Apple lost the fight over the version it had already abandoned, and won the fight over the version it now ships.

The scoreboard is messier than 'Apple lost': one courtroom, one patent, one verdict — none of them the whole war

Read the headlines and you'd think Apple simply lost to Masimo. The record is more mixed, and the differences are load-bearing. Apple has said that across its broader legal fight with Masimo, the majority of the more than 25 patents Masimo has asserted against it have been found invalid — with the ITC's exclusion order itself ultimately resting on just two.⁹ Apple also won a parallel countersuit: in October 2024 a Delaware jury found Masimo's own W1 and Freedom watches willfully infringed two Apple design patents — awarding Apple the almost comically small sum of $250, a legal flag planted more than a payday.⁵

Then there is the number everyone cites: $634 million. It is real, and it stings, but it does not come from the blood-oxygen import case at all. In November 2025 a California federal jury upheld Masimo Patent No. 10,433,776 — covering the Apple Watch's heart-rate alert feature rather than the blood-oxygen sensing at issue in the import ban¹⁰ — found Apple infringed it, and handed Masimo $634 million.⁶ Conflating that verdict with the import ban is the single most common error in coverage of this fight. The two run on separate tracks, over separate patents, and Apple's blood-oxygen detour succeeded even as the other track cost it dearly. That is the shape of a real war: you can win the battle you engineered around and still bleed on the one you didn't.

Wasn't the detour just an expensive way to lose slower?: the honest counter is that Apple is still paying — the question is what it bought

The fair objection is that this looks like a lot of lawyering to avoid an outcome Apple reached anyway. It shipped crippled watches for over a year, absorbed a $634 million verdict on the adjacent patent, and burned an enormous amount of legal effort — all to dodge a license it might have negotiated in an afternoon. If the goal was to stop paying Masimo, the scoreboard shows Masimo still getting paid.⁶

But that reading confuses a jury verdict with a license, and the difference is the entire point. A one-time damages award — even a large, appealable one — ends. A license does not: it is a permanent, rival-priced tax on every future watch, escalating with every model, with Masimo holding the meter. By refusing to license, Apple kept the price of the dependency at zero going forward and moved the technology to ground the exclusion order can't reach.⁸ The detour did not make the fight free. It made the fight finite. Apple traded a recurring bill it would never control for a set of one-off costs it could litigate, appeal, and eventually outlast.

Apple's blood-oxygen fight was never really about a feature. It was about who owns the road a feature travels on. Given a choice between renting that road from a rival forever and building its own detour at a bruising one-time cost, Apple built the detour — shipping a deliberately hollowed-out watch as the price of keeping its options open. By 2026 the redesign was clearing the very tribunal that once banned it, even as a separate verdict reminded everyone the war isn't over.⁸ The lesson isn't that fighting always beats licensing. It's that the most expensive number on a patent case is rarely the one in the headline — it's the recurring one you agree to pay when you decide it's easier to just settle.