The US blood oxygen ban was never lifted - Apple worked around it. Which Apple Watch models have SpO2 in 2026 and how the iPhone-calculated version works.
Quick answer: The US import ban was never lifted, overturned, or settled — Apple engineered around it. On US Apple Watches bought since 18 January 2024, the sensor still takes the reading on your wrist, but the calculation happens on your paired iPhone and the result appears in the Health app rather than on the watch. Watches bought outside the US, and US watches bought before that date, are completely unaffected.
Source check: August 31, 2026. Device behaviour is taken from Apple's own current support documentation and product specification pages, checked on the date of writing. Legal milestones come from the Federal Circuit opinion, ITC determinations and the Federal Register. Where reporting and primary records disagree, the primary record is used.
What Actually Happened
The short version, because the coverage has been genuinely confusing.
Masimo brought a case at the US International Trade Commission over two pulse-oximetry patents. In October 2023 the ITC found a violation and issued a limited exclusion order. Apple pre-emptively pulled Series 9 and Ultra 2 from US sale that December, and after a brief stay the ban took effect in January 2024.
Apple resumed US sales on 18 January 2024 with the blood oxygen feature disabled in software. That is the state most people remember: you could buy the watch, the sensor was physically present, and the feature simply did not work.
In August 2025 Apple shipped a genuine workaround in iOS 18.6.1 and watchOS 11.6.1. That is what US owners have today, and it is a meaningfully different thing from the feature being switched off.
How the Workaround Works
Apple's own description is that sensor data from the Blood Oxygen app is measured and calculated on the paired iPhone, with results viewable in the Respiratory section of the Health app.
In practice that means the hardware on your wrist still does the sensing. What moved is the computation and the display. You will not see a number appear on the watch face the way non-US users do — you take the measurement, then read the result on your phone.
The legal logic behind this matters and is genuinely clever. The asserted patents cover a device that does the whole job in one place. Splitting the work across a watch and a separate paired phone means the accused combination is no longer what the patent claims describe.
The practical cost is real but modest: you need your iPhone nearby, and it is an extra step. If a measurement is taken away from the phone, it is processed once the two are back together.
Which Models Have Blood Oxygen in 2026
Two separate questions decide this, and conflating them is where most confusion comes from. First, does the watch have the sensor at all? Second, where and when did you buy it?
- Apple Watch Series 11 — has the sensor. US units use the iPhone-calculated form from launch.
- Apple Watch Ultra 3 — has the sensor. Same iPhone-calculated behaviour in the US.
- Apple Watch SE 3 — has no blood oxygen sensor at all. This is not a legal restriction; the hardware simply is not there. It also has no electrical heart sensor. We checked Apple's specification page directly, because some comparison tables get this wrong.
- Series 9, Series 10, Ultra 2 — have the sensor. US units shipped with the feature disabled from January 2024 and regained it in iPhone-calculated form with the August 2025 update.
If you are shopping and blood oxygen matters to you, the single most important thing to know is that SE 3 does not have it in any form, anywhere in the world. That is a hardware decision unrelated to the litigation, and no software update will change it.
How to Tell Which Version You Have
Apple draws the line by part number. US models purchased on or after 18 January 2024 have part numbers ending in LW/A, and those are the ones that route the calculation to the iPhone.
You can find the part number in Settings on the watch under General, then About. If yours does not end in LW/A, you have the original implementation with the reading shown on the watch.
Apple has been explicit that there is no impact on units purchased before the change, nor on any unit purchased outside the United States. Nothing was removed retroactively from a watch anyone already owned.
How the Dispute Actually Ended
This is where almost every summary goes wrong, because two contradictory-sounding things are both true.
In March 2026 the Federal Circuit affirmed the ITC against Apple. Apple lost that appeal comprehensively, and after a rehearing request was denied in late July 2026 the mandate issued. The exclusion order on the original on-watch design is final.
Separately, the ITC ran a proceeding specifically to test whether the redesigned, iPhone-calculated version infringes. In mid-March 2026 an administrative law judge found it does not. In April 2026 the full Commission declined to review that finding, concluding the redesigned products should not be excluded, and terminated the proceeding. Masimo's parallel challenge to the customs ruling that had blessed the redesign was dismissed with prejudice shortly afterwards.
So: the original design remains barred from import, and the redesign is separately cleared. Apple lost the appeal about the old product and won the fight about the new one. Both outcomes stand.
Anyone telling you "the Apple Watch blood oxygen ban is over" is describing this inaccurately. The ban was not lifted. Apple built something the ban does not cover. As of this writing Apple has not restored on-watch calculation for US models, and its live documentation still describes analysis happening on the iPhone.
One more thing that changed
Masimo itself is no longer independent — Danaher completed its acquisition in June 2026, and Masimo now operates as a Danaher subsidiary. Litigation between the companies has continued regardless.
The $634 Million Verdict Is a Different Case
You will see this figure attached to blood oxygen stories. It does not belong there.
A California jury awarded Masimo roughly $634 million in late 2025 over Apple Watch heart-rate monitoring and notification features, on a patent that had already expired in 2022. It is a separate case in a separate court about separate functionality, and it has no bearing on whether blood oxygen works on your watch.
It is also not final. Both sides have appealed, and execution of the judgment has been stayed pending that appeal — despite headlines describing the payment as settled.
What This Means If You Are Buying
If you are in the US and want blood oxygen, buy Series 11 or Ultra 3 and accept that readings appear on your iPhone. It works, it is supported, and it is not going away.
If you are buying an SE 3 for someone specifically because they want oxygen readings, buy something else — the sensor does not exist in that model.
And if you already own a pre-2024 US watch or one bought abroad, change nothing. You have the original on-watch implementation and no update has taken it away.
For what the readings are actually worth clinically, see our review of Apple Watch SpO2 accuracy against clinical data — availability and accuracy are separate questions, and the second one matters more.
Bottom Line
Blood oxygen works on current US Apple Watches, just not the way it works elsewhere: the watch measures, the iPhone calculates, the Health app displays. The exclusion order on the original design is final and was affirmed on appeal; the redesign was separately cleared and is what you are buying today. The only model where the feature genuinely does not exist is the SE 3, and that is a hardware choice rather than a legal one.
Related iPhoneExtra Guides
More from iPhoneExtra: Apple Watch SpO2 Accuracy Tested | Apple Watch Series 11 Health Sensors Tested | Apple Watch ECG Accuracy.
