Apple brings back blood oxygen tracking to Apple Watch models in the US

Apple Watch

Apple will roll out iOS 18.6.1 and watchOS 11.6.1 later today, reintroducing a “redesigned Blood Oxygen feature” for Apple Watch users in the United States. The update applies to Apple Watch Series 9, Series 10, and Ultra 2 models purchased in the US without the original Blood Oxygen app, specifically those with part numbers ending in LW/A.

The revised feature shifts measurement processing from the watch to the paired iPhone, with results displayed in the iOS Health app. This workaround appears to sidestep the patent dispute with medical technology firm Masimo, which has kept the feature off new Apple Watches in the US since January 2024.

The conflict began years ago, centring on Masimo’s patents for pulse oximetry technology. It escalated in December 2023 when an import ban temporarily halted US sales of Apple Watch models with the feature. Apple resumed sales by removing Blood Oxygen tracking from affected devices, a limitation that has persisted through the launch of the Series 10.

Today’s update marks the first time Apple has offered a form of Blood Oxygen monitoring to US buyers of these stripped-down models, though it functions differently from the original.

To check eligibility, users can open the Settings app on their Apple Watch or the Apple Watch app on their iPhone, navigate to General → About, and confirm the part number.

With this software update, Apple is giving affected Watch owners back a popular health feature — but in a legally compliant, redesigned format.