Apple is flipping the switch back on for blood oxygen measurements in recent US Apple Watch models — but the feature won’t work the way it used to. A new software update reintroduces pulse oximetry after it was pulled in early 2024 due to a patent dispute with medical device maker Masimo.
From import ban to software workaround for Apple Watch
The International Trade Commission had banned the sale of Apple Watches in the US with the original blood oxygen tech, ruling that it infringed Masimo’s patents. The restriction forced Apple to ship Series 9, Series 10, and Apple Watch Ultra 2 units without the capability.
Now, through iOS 18.6.1 and watchOS 11.6.1, Apple has reworked the system. For models purchased in the US after January 18, 2024 with part numbers ending in LW/A, the Watch will no longer show readings directly on the device. Instead, data will be processed by an iPhone and viewed in the Health app. Watches sold before the ban — or outside the US — remain unaffected.
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Wellness, not diagnosis
Apple emphasizes that its blood oxygen tool is for wellness tracking, not medical use. The FDA hasn’t cleared it for diagnosing conditions, and studies have noted occasional outlier readings compared to clinical devices. Researchers have also questioned its usefulness for the general public, warning that irregular numbers could cause unnecessary worry.
Still, the feature became popular during the COVID pandemic and has been credited anecdotally with alerting some users to potential health problems.
A careful comeback from Apple
By shifting the core analysis to the iPhone, Apple appears to have sidestepped the patent claims while restoring a high-profile selling point. Whether this workaround satisfies regulators — and Masimo — remains to be seen.
For now, Apple Watch owners in the US can once again keep an eye on their oxygen levels, though they’ll have to look to their phone for the results.
