Overview

• Apple re-enabled blood oxygen tracking on August 14 with iOS 18.6.1 and watchOS 11.6.1 for Apple Watch Series 9, Series 10 and Ultra 2 models sold in the U.S.
• The watch collects raw sensor data, the paired iPhone performs the measurement, and results appear in the Health app’s Respiratory section rather than on the watch.
• The redesigned implementation supports background readings with data saved in the iPhone’s Health app.
• A recent U.S. Customs decision cleared the workaround even as the ITC exclusion order tied to Masimo’s patent case remains; watches sold before mid‑January 2024 or outside the U.S. keep the original on‑watch feature.
• Developers now see the same redesign in iOS 26 and watchOS 26 beta 7, and Apple continues to label the tool as a wellness feature for users 18 and older.