Apple is bringing back the blood oxygen monitoring feature for some Apple Watch models in the United States after a recent U.S. Customs ruling allowed it to do so. The affected models include Apple Watch Series 9, Series 10, and Apple Watch Ultra 2. This feature had been removed in early 2024 due to a patent dispute with medical technology company Masimo, which had won a legal ruling blocking Apple’s import of watches with the blood oxygen feature.
The return of the feature is enabled by software updates: iOS 18.6.1 for iPhones and watchOS 11.6.1 for Apple Watches. The updated feature works by measuring and calculating blood oxygen data on the paired iPhone rather than directly on the watch, as a workaround to avoid the patent infringement issues. Users will be able to view their blood oxygen results in the Respiratory section of the Health app on their iPhone.
This redesigned blood oxygen feature will not affect Apple Watch units purchased before 2024 or those bought outside the U.S. The update restores a key health-tracking capability that was first introduced in 2020 with the Series 6 and had become a significant part of Apple’s health functionalities, especially highlighted during the Covid-19 pandemic. The reintroduction comes ahead of Apple’s anticipated September event where new Apple Watch models are expected to be unveiled.
Overall, this marks a major development in Apple’s ongoing legal and technological challenge related to blood oxygen monitoring on its smartwatches. The company emphasizes that the updated feature adheres to privacy and scientific standards while empowering users with health insights.
In summary:
- Blood oxygen monitoring is returning to Apple Watch Series 9, Series 10, and Ultra 2 in the U.S.
- Enabled by iOS 18.6.1 and watchOS 11.6.1 updates.
- Measurement and calculation now done on the paired iPhone.
- Result display in the Respiratory section of the Health app.
- This follows a U.S. Customs ruling after a patent dispute with Masimo.
- Feature was initially removed in early 2024 to comply with import bans.
- Not affecting earlier models or purchases outside the U.S.
This updated feature release is from August 14, 2025.businessinsider+9