Apple has officially reintroduced the Blood Oxygen monitoring feature for Apple Watch Series 9, Series 10, and Ultra 2 models in the U.S., following an absence of over a year. This was achieved with the rollout of iOS 18.6.1 for iPhones and watchOS 11.6.1 for the respective watch models. The timing of the update coincides with a recent U.S. Customs ruling that lifted earlier restrictions, enabling Apple to comply with legal requirements while restoring the function.
Because of a patent dispute with medical tech firm Masimo, the original Blood Oxygen feature was disabled on watches sold in the U.S. after January 2024. In the new design, the Apple Watch still takes sensor readings, but the data is transferred to a paired iPhone, where it is processed and displayed in the Health app’s Respiratory section—not on the watch face itself.
This redesigned setup ensures users regain access to Blood Oxygen tracking, albeit via a two-device experience. It’s a clever workaround that aligns with the legal constraints while preserving core functionality for health-conscious Apple Watch owners.
Sources
- Apple returns blood oxygen monitoring to the latest Apple Watches
https://www.theverge.com/news/759158/apple-watch-blood-oxygen-redesign-import-ban-wearables-smartwatch - What Apple’s big win with its blood oxygen feature means for your watch
https://www.businessinsider.com/apple-brings-blood-oxygen-feature-back-some-apple-watch-models-2025-8 - Blood Oxygen tracking is back on the Apple Watch – but it’s now a two-device experience
https://www.techradar.com/health-fitness/smartwatches/blood-oxygen-tracking-is-back-on-the-apple-watch-in-the-us-but-its-now-a-two-device-experience - Apple Watch Blood Oxygen sensing is back
https://www.wired.com/story/apple-watch-blood-oxygen-sensing-is-back - Apple newsroom: An update on Blood Oxygen for Apple Watch in the US
https://www.apple.com/newsroom/2025/08/an-update-on-blood-oxygen-for-apple-watch-in-the-us
