Apple Brings Blood Oxygen Feature Back to Some Apple Watches

It may be time to update your Apple Watch if you want to unlock the return of blood oxygen monitoring.

Apple is releasing updates to reactivate a redesigned version of the feature for some Series 9, Series 10, and Ultra 2 models, the company said in a statement on Thursday. The tech enables Apple Watch users to monitor their blood oxygen levels.

The return of blood oxygen monitoring to Apple Watches is a big win for Apple. The company introduced the feature in 2020 as part of a push to beef up its health-tracking capabilities to compete with rival smartwatches. But the blood oxygen monitor was beset by a patent dispute with medtech company Masimo.

Apple began removing the feature from some Apple Watch models in 2024 to circumvent an import ban. In 2023, the International Trade Commission found that certain models violated Masimo’s patent and later blocked Apple from importing watches with the feature into the US. The Series 10, which launched after the ban, was initially sold in the US without the blood oxygen feature.

Apple said Thursday that a recent US Customs ruling allowed it to bring a redesigned version of the feature to the affected models.

An iOS 18.6.1 update for iPhones and a watchOS 11.6.1 update will make blood oxygen monitoring available to those who bought watches with the feature disabled, Apple said. The update enables a paired iPhone to measure and calculate the data from the Blood Oxygen app, and the results to be viewed in the Respiratory section of the Health app.

Those who bought the affected Apple Watch models outside the US or purchased an Apple Watch without the original Blood Oxygen feature disabled won’t be affected by the update, Apple said.