Overview

• Software updates iOS 18.6.1 and watchOS 11.6.1 re-enable SpO2 readings on U.S. Apple Watch units beginning August 14, 2025.
• The redesigned feature collects blood-oxygen data on the watch and processes it on the iPhone Health app rather than natively on the device.
• Returns hinge on a U.S. Customs and Border Protection decision that cleared imports of watches with redesigned pulse-oximetry systems.
• The feature had been removed in 2023 after the U.S. International Trade Commission ruled that Apple infringed Masimo patents, and both companies continue to litigate over the technology.
• Coverage differs on which models qualify—some outlets cite Series 8, 10 and Ultra while others list Series 9, 10 and Ultra 2—creating uncertainty about device eligibility.