After more than a year of absence due to a patent dispute, Apple has officially restored the Blood Oxygen monitoring feature to Apple Watch models sold in the United States. The new version of the feature arrives on specific Apple Watch Series 9, Series 10, and Ultra 2 devices through a software update, marking the return of a key health tool for US users.
The restoration comes as part of iOS 18.6.1 and watchOS 11.6.1 updates released on August 14, 2025. This “redesigned” Blood Oxygen feature works differently than before: while the sensors on the Apple Watch continue to collect the necessary data, the crucial computation of blood oxygen levels is now handled by the paired iPhone. Users can view the blood oxygen results in the Respiratory section of the Health app on their iPhone instead of directly on the watch.
This workaround was made possible by a recent ruling from U.S. Customs allowing Apple to circumvent the prior import ban, which had been enforced since December 2023 as a result of a patent infringement case filed by health technology company Masimo. That ban forced Apple to disable the Blood Oxygen feature on new Apple Watch models sold in the US starting January 2024, disappointing many customers.
Apple emphasized that this update only affects US models sold after January 17, 2024, and does not alter Apple Watches bought before that or devices sold outside the US, which still retain the original blood oxygen monitoring functionality.
The company continues to appeal the original patent ruling, so the legal battle is ongoing. Meanwhile, Apple Watch Series 9, Series 10, and Ultra 2 models in the US regain an important health capability. These watches also come equipped with other health and wellness tools including irregular rhythm notifications, ECG, sleep apnea notifications, fall detection, sleep tracking, wrist temperature sensing, and more.
This update is a significant win for Apple and its customers in the US, restoring a vital health monitoring feature through a clever technical solution that navigates around ongoing legal constraints. It highlights Apple’s commitment to providing advanced health technology while respecting legal boundaries and preserving user privacy.
The return of the Blood Oxygen feature enhances the Apple Watch’s role as a comprehensive health and fitness companion for users in the US market once again.