**Apple Unveils watchOS 11.6.1: Blood Oxygen Application Restored for Select Users**
Apple has officially released watchOS 11.6.1 for the Apple Watch, representing a major update that reinstates the Blood Oxygen application for specific users in the United States. This release aligns with the launch of iOS 18.6.1, which improves compatibility and capabilities between the Apple Watch and iPhone. Importantly, this is the first instance the Blood Oxygen feature has been available on new watch models since late 2023.
Earlier, individuals trying to use the Blood Oxygen app on the affected devices received a notification indicating, “The Blood Oxygen app is no longer available. Learn more in the Health app on your iPhone.” This restriction impacted Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 models sold in the U.S. due to a patent conflict with medical technology firm Masimo, leading Apple to deactivate the feature.
With the rollout of watchOS 11.6.1 and iOS 18.6.1, Apple has introduced a revamped version of the Blood Oxygen feature. The updated approach moves the calculation of blood oxygen levels from the watch to the associated iPhone. While the Apple Watch still gathers the essential sensor data, the analysis now occurs on the iPhone, with results shown in the Health app. Although this modification might be less convenient than receiving immediate readings directly on the watch, it offers a practical solution for users who have previously lacked this capability.
Moreover, background blood oxygen readings have been reinstated with this new technique, further boosting the health tracking features of the Apple Watch.
Apple confirms that the update is accessible to users of Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 in the U.S. who had not previously accessed the original Blood Oxygen feature. As the company continues addressing the ongoing legal issues, this workaround reinstates access to oxygen saturation information in an altered format.
To upgrade to watchOS 11.6.1, users can proceed via the Watch app on their iPhone by going to General > Software Update after updating to iOS 18.6.1.
**Release Notes:**
This update introduces a new Blood Oxygen experience for users in the United States with Apple Watch Series 9, Series 10, and Apple Watch Ultra 2. Measurements are computed on iPhone and displayed in the Health app.
For details on the security content of Apple software updates, please check [Apple’s support page](https://support.apple.com/100100).
Looking forward, iOS 26 and watchOS 26 are presently in developer and public beta phases and do not yet include this revamped Blood Oxygen method. As there is no user-supported option to downgrade the Apple Watch from the beta, users remain hopeful that this workaround will be integrated into upcoming beta builds, as both significant updates are anticipated next month.
