Tech Desk 
Aug 14, 2025
Apple is reinstating its blood oxygen measurement feature for certain models of its watch in the US through a newly approved software update from US Customs.
The updated software is going to allow Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 users in the US to check their blood oxygen levels. The data to do that will be collected by the watch sensors but will be processed on the iPhone, which is paired to the watch.
Apple released blood oxygen tracking in the Apple Watch Series 6 in 2020, giving health-minded users the ability to measure their own oxygen saturation.
But the feature was dropped in newer models (sold in the US) when Masimo accused Apple of stealing its technology, and it received a US International Trade Commission (ITC) ruling against their US imports of watches featuring that ability.
The legal fight commenced after Masimo purported Apple had hired its people and pilfered its ideas for their proprietary health technology after discussions of a possible partnership.
In 2023, the ITC ruled in Masimo’s favour, leading to a temporary sales ban on Apple’s Series 9 and Ultra 2 in the US.
Apple briefly resumed sales after an appeal but was forced to remove the pulse oximetry function again when the ban was reinstated.
Notably, with customs clearance, Apple is reactivating the feature for affected models via a software update. Masimo shares fell 4.5% after the announcement.
The blood oxygen app works by starting a reading session on the Apple Watch, which uses sensors to gather data. The iPhone then calculates and shows the oxygen level. Apple says this restores an important health and wellness tool for US users after months of restrictions.
