Apple Watch Blood Oxygen Returns in U.S. After 18-Month Gap

Apple reintroduces blood oxygen monitoring on Series 9, 10, and Ultra 2 in the U.S. via iOS 18.6.1 and watchOS 11.6.1 updates, bypassing patent restrictions.

Apple is bringing back its blood oxygen monitoring feature on some Apple Watch models in the U.S. This is the same feature that first came out with the Series 6 back in 2020. It had been removed from the Series 9, Series 10, and Ultra 2 models sold in the U.S. The reason it was pulled? A patent fight with a medical tech company called Masimo. That dispute even led to a ruling from the U.S. International Trade Commission in 2023, which put an import ban on some Apple Watches that had the feature.

To follow the court ruling, Apple had to make some changes to how the blood oxygen monitoring works on its watches. Instead of the watch doing the entire math and processing on its own, the sensor now sends the data over to your iPhone, where it gets measured and calculated. This means you’ll need to open the Health app on your iPhone to see your blood oxygen levels, which are displayed in the Respiratory section. Apple made sure this update works smoothly with the latest software, so you’ll need iOS 18.6.1 on your iPhone and watchOS 11.6.1 on your Apple Watch to get it. The good news is that you can download the update wirelessly, right over the air, without needing to plug anything in or visit a store. This approach keeps the feature available while making sure Apple stays in line with the legal requirements.

The new version of the feature is available to U.S. customers who bought the affected Apple Watch models after January 18, 2024, and whose serial numbers end with “LW/A.” If you got your watch before that date, or bought it outside the U.S., this update doesn’t apply to you. Apple decided to bring the feature back after a favorable ruling from U.S. Customs, which cleared the way for them to offer it again while following all the legal rules.