Apple has just released iOS 18.6.1 for iPhones and watchOS 11.6.1 for Apple Watch users — and the big news is that the Blood Oxygen Monitoring feature is finally back in the United States.
Apple has rolled out the latest iOS 18.6.1 and watchOS 11.6.1 updates, and this release brings back something Apple Watch users in the U.S. have been missing for a long time — Blood Oxygen Monitoring.
This update isn’t just another routine bug fix. It’s a highly requested comeback feature that makes the Apple Watch once again one of the most complete health-tracking devices on the market.
Why the Blood Oxygen Feature Matters
Blood Oxygen (SpO2) tracking is a popular tool for fitness enthusiasts and health-conscious users. It lets you measure how well your body absorbs oxygen, giving insights into sleep quality, workouts, and overall respiratory health.
Apple was forced to disable this feature in the U.S. back in 2024 due to a patent dispute, which frustrated many users of the Apple Watch Series 9, Series 10, and Ultra 2. With the latest update, Apple has finally restored it — but with a smart twist.
What’s New in iOS 18.6.1?
- Blood Oxygen Monitoring Returns: The feature now works again, but instead of being processed on the watch itself, the data is analyzed on the paired iPhone.
- Results in Health App: You can find your readings in the Respiratory section of the Health app.
- Compatible Models: Available for Apple Watch Series 9, Series 10, and Ultra 2 sold in the U.S.
How to Enable the Feature
- Update your iPhone to iOS 18.6.1 by going to Settings → General → Software Update.
- Open the Watch app and update your watch to watchOS 11.6.1.
- Wait up to 24 hours for the Blood Oxygen feature to fully activate. Opening the Health app or ECG app can speed up the process.
Any Other Fixes?
Apple has not included major security patches or bug fixes in this update. The sole focus was to bring back Blood Oxygen Monitoring to U.S. users.
The Bottom Line
The iOS 18.6.1 update is a must-install for Apple Watch users in the United States. By restoring Blood Oxygen Monitoring, Apple has once again given its users access to an essential health tool that had been missing for over a year.
If you own a Series 9, Series 10, or Ultra 2, make sure to update your devices today to unlock this feature.