If you bought an Apple Watch in the United States between January 2024 and August 2025, you likely noticed the Blood Oxygen app was missing — even though the sensor hardware was sitting right there on your wrist. The reason had nothing to do with safety or accuracy. It was the result of a patent dispute: the US International Trade Commission (ITC) ruled that Apple’s pulse oximetry feature infringed patents held by medical device company Masimo, triggering an import ban. Apple’s workaround was to disable the feature in software on US-sold units. In August 2025, Apple restored a redesigned version of the feature through a software update — so this is the full story of the apple watch blood oxygen feature US import ban, explained.
- The feature was removed for legal reasons, not because it was unsafe or inaccurate
- Only watches sold in the US after mid-January 2024 were affected; earlier purchases and international models kept it
- A redesigned version returned in August 2025, with measurements calculated on the paired iPhone instead of the watch
The short version: a patent fight, not a product flaw
Masimo, a California-based medical technology company known for hospital-grade pulse oximeters, accused Apple of infringing its light-based blood oxygen sensing patents. In October 2023, the ITC agreed and issued a limited exclusion order — effectively a ban on importing Apple Watch models that included the infringing pulse oximetry feature. Because Apple assembles its watches overseas, an import ban is close to a sales ban for new US inventory.
The order took effect in late December 2023. After a brief pause during appeals, Apple chose a software fix: starting January 18, 2024, Apple Watch Series 9 and Ultra 2 units sold in the US shipped with the Blood Oxygen app disabled. The red and infrared LEDs were still physically present; tapping the app simply told users the feature was unavailable. Crucially, the ITC case was about intellectual property. No regulator questioned whether the readings were safe, and the feature continued working normally everywhere else in the world.
Timeline of the dispute
- 2020: Apple Watch Series 6 debuts blood oxygen sensing; Masimo sues, alleging patent infringement and trade-secret misuse.
- October 2023: The ITC finds Apple infringed Masimo pulse oximetry patents and issues an import ban.
- December 26, 2023: The ban takes effect. Apple briefly pulls Series 9 and Ultra 2 from its US stores, then resumes sales during a short court-ordered pause.
- January 18, 2024: After the pause is lifted, Apple resumes US sales with the Blood Oxygen feature disabled in software.
- September 2024: Apple Watch Series 10 launches in the US with the same restriction, despite having the sensor hardware.
- August 14, 2025: Apple releases iOS 18.6.1 and watchOS 11.6.1, restoring a redesigned Blood Oxygen feature for affected US models after US Customs approved the workaround.
Which models were affected?
| Model | SpO2 hardware | US status during the ban | Status after the August 2025 update |
|---|---|---|---|
| Series 6, 7, 8 (and Series 9/Ultra 2 bought before Jan 18, 2024) | Yes | Feature kept working | Unchanged — original on-watch feature |
| Series 9 / Ultra 2 (US units sold after Jan 18, 2024) | Yes (disabled) | Blood Oxygen app unavailable | Redesigned feature enabled via update |
| Series 10 (US units) | Yes (disabled) | Blood Oxygen app unavailable | Redesigned feature enabled via update |
| Apple Watch SE (all generations) | No sensor | Never had the feature | Still no SpO2 sensing |
| Models sold outside the US | Yes | Unaffected | Unchanged — original feature |
How Apple brought the feature back
Apple’s redesigned version, released August 14, 2025, changes where the blood oxygen result is calculated rather than how the light-based sensor works. On affected US models, the watch still collects sensor data, but the measurement is computed on the paired iPhone and displayed in the Respiratory section of the Health app — instead of being calculated and shown directly on the watch. US Customs and Border Protection ruled that this redesigned approach fell outside the scope of the import ban, which is what allowed Apple to ship it while the broader Masimo litigation continued. To get it, affected watches need watchOS 11.6.1 (or later) paired with an iPhone on iOS 18.6.1 (or later).
Does any of this change how useful SpO2 readings are?
The legal fight says nothing about measurement quality — but it’s worth keeping wrist-based pulse oximetry in perspective. Apple has always positioned Blood Oxygen as a wellness feature, not a medical device, and published research consistently shows wrist readings are more variable than fingertip pulse oximeters, especially during movement or with poor sensor contact. We cover the technology and its accuracy limits in depth in our guide to what SpO2 on a smartwatch actually measures.
It’s a similar story to other wrist-based health metrics: useful for spotting trends, not for diagnosis. See our related explainers on what a smartwatch ECG actually measures and whether a smartwatch can detect AFib.
Frequently asked questions
Was the Blood Oxygen feature removed because it was inaccurate or unsafe?
No. The removal was purely about patent law. The ITC found that Apple’s implementation infringed Masimo’s pulse oximetry patents, which blocked imports of watches with the feature enabled. Neither the FDA nor any other safety regulator ordered the feature removed, and it kept working on international models throughout.
How do I know if my Apple Watch has the redesigned version?
If you bought a Series 9, Series 10, or Ultra 2 in the US after January 18, 2024, and you’ve updated to watchOS 11.6.1 or later with a paired iPhone on iOS 18.6.1 or later, your watch uses the redesigned feature: you take the measurement on the watch, and the result appears in the iPhone’s Health app under Respiratory. Watches purchased earlier, or outside the US, show results directly on the watch as before.
Is the Apple–Masimo dispute over?
Not entirely. The Customs ruling cleared the redesigned feature for import, but the underlying patent litigation and appeals between Apple and Masimo have continued in court. The practical situation for US buyers, however, has been stable since August 2025: new Apple Watches with SpO2 hardware ship with the redesigned blood oxygen feature working.
Did the ban affect other health features like ECG or heart rate?
No. Heart rate tracking, ECG, high/low heart rate alerts, irregular rhythm notifications, sleep tracking, and temperature sensing were never part of the case. Only the blood oxygen (pulse oximetry) feature was covered by the import ban.
This article is general information, not medical advice. Smartwatch blood oxygen readings are wellness estimates and should not be used to diagnose or manage any condition. Always consult a qualified healthcare professional about symptoms or concerns.