A redesigned blood oxygen measurement capability will arrive Thursday for Apple Watch models that lost access to the feature due to a patent dispute.
Apple found a workaround that involves the Apple Watch testing the user’s blood oxygenation level, then displaying the reading on a paired iPhone.
Update: Apple released iOS 18.6.1 and watchOS 11.6.1 with the promised workaround.
Apple Watch gets blood oxygen sensing back, but not the app
As discussed in a recent Cult of Mac editorial, Apple is involved in a patent-infringement battle with Irvine, California-based Masimo Corp. and its sibling company, Cercacor Laboratories. And Apple keeps losing, to the point that the International Trade Commission banned the import into the United States of Apple Watches that use the disputed technology.
However, a recent U.S. Customs ruling enabled Apple to come up with a workaround. This doesn’t fully bring the missing Blood Oxygen app back to Apple Watches that lost it. However, users gain the same functionality via exchanging information between the smartwatch and an iPhone.
“Sensor data from the Blood Oxygen app on Apple Watch will be measured and calculated on the paired iPhone, and results can be viewed in the Respiratory section of the Health app,” Apple said Thursday in a press release announcing the return of the missing feature.
Good for many US Apple Watch wearers
The change only affects people who bought a new Apple Watch Series 9, Apple Watch Series 10 or Apple Watch Ultra 2 in the United States since early 2024. Due to a court order, those models did not come with Apple’s Blood Oxygen app enabled.
To gain the same functionality as the app, members of this group need to install iOS 18.6.1 on their iPhones and watchOS 11.6.1 on their Apple Watches. As noted, Apple released the operating system updates today.
As part of our ongoing goal to help you live a healthier life, we launched a redesigned Blood Oxygen feature for Apple Watch Series 9, Series 10, and Ultra 2 users in the US today!
Download the latest software to try it out.
— Greg Joswiak (@gregjoz) August 14, 2025
Apple Watch users outside the United States, and anyone who bought a device before early 2024, still have the Blood Oxygen app. They shouldn’t be affected by the change in functionality Apple just announced.
Another group benefiting from the change is anyone in the United States interested in an Apple Watch Series 11 or Ultra 3, which are expected to launch in September. These new versions can now include blood oxygen sensing when sold in the United States.
