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Yes—Apple Watch Blood Oxygen returned in the United States on August 14, 2025. The restoration applies to certain U.S. Apple Watch Series 9, Series 10, and Ultra 2 units that were sold with Blood Oxygen disabled. It requires iOS 18.6.1 on the paired iPhone and watchOS 11.6.1 on the watch.
This is not an unrestricted return of the original watch-based experience. The watch collects the sensor data, while the paired iPhone performs the measurement calculation and displays the result in the Health app’s Respiratory section.
Which Apple Watches are eligible?
| Watch or configuration | August 2025 restoration | What to know |
|---|---|---|
| U.S. Apple Watch Series 9 | Potentially eligible | Only units sold without Blood Oxygen are the target of the update. |
| U.S. Apple Watch Series 10 | Potentially eligible | Eligibility depends on the U.S. configuration and prior feature status. |
| U.S. Apple Watch Ultra 2 | Potentially eligible | Not every Ultra 2 automatically receives the redesigned feature. |
| Older U.S. watches | Not the target of this restoration | Some Series 6–8 and Ultra units may already retain the original feature, depending on when and where they were purchased. |
| International Apple Watches | No change | Units purchased outside the United States were not altered by this U.S. rollout. |
A watch’s model name alone is not enough to establish eligibility. A Series 9, Series 10, or Ultra 2 bought in the U.S. before Blood Oxygen was disabled may already have the original functionality, while a used or imported watch may have a different regional configuration.
What happened on August 14, 2025?
Apple announced and began rolling out a redesigned Blood Oxygen feature for affected U.S. watches on August 14, 2025. The required software versions were iOS 18.6.1 and watchOS 11.6.1.Wareable reported that the paired iPhone handles the calculation, with results appearing in Apple Health rather than through exactly the same on-watch workflow used by unaffected models.
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- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
The update does not require eligible owners to buy a new watch. The relevant sensor hardware was already present in affected units; the feature had been disabled in software. This was therefore a software and processing redesign, not the launch of a new sensor or Apple Watch generation.AppleInsider’s coverage linked the change to a recent U.S. Customs ruling.
Why was Blood Oxygen disabled in U.S. Apple Watches?
Apple’s Blood Oxygen feature, introduced with Apple Watch Series 6 in 2020, became entangled in a patent dispute with Masimo over pulse-oximetry technology. The U.S. International Trade Commission found that Apple infringed Masimo patents, leading to an import restriction affecting Apple Watch sales in the United States.
Following the dispute, Apple began selling affected U.S. models without an operational Blood Oxygen feature in late 2023 and January 2024. Reports identify January 17–18, 2024 as an important transition period, although the exact description of the change varies by model and sales channel.Bloomberg’s timeline covers the import restriction and later return.
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- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
It is more accurate to say that the feature was disabled than that Apple removed the sensor from every affected watch. The August 2025 solution restored usable Blood Oxygen functionality through a different software workflow. The Customs ruling enabled the change, but that should not be read as proof that every aspect of the broader Masimo dispute was permanently settled.
How the redesigned Blood Oxygen feature works
The practical difference is where processing takes place:
Redesigned U.S. workflow: watch sensors → paired iPhone calculation → Health app, Respiratory section.
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- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
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- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
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The original implementation centered more of the processing and result experience on the Apple Watch itself. The redesigned U.S. version depends more heavily on the paired iPhone, so it is not simply the old watch-only feature switched back on.
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- You need the watch paired with an iPhone that supports the required software.
- You should look for results in the iPhone’s Health app, under Respiratory.
- The experience may be less convenient when you leave the iPhone behind.
- Behavior can differ from an international Apple Watch or an older U.S. watch that retained the original feature.
The available coverage establishes the iPhone’s role in calculation and viewing, but it does not justify promising that every reading requires the iPhone to be physically nearby at the instant the watch collects data.
How to enable Blood Oxygen
1. Update the iPhone
- Open Settings.
- Tap General, then Software Update.
- Install iOS 18.6.1 if it is offered.
2. Update the Apple Watch
- Charge the watch to at least 50%.
- Place it on its charger and connect it to Wi-Fi.
- On the paired iPhone, open the Apple Watch app.
- Tap General, then Software Update.
- Install watchOS 11.6.1 and follow the prompts.
- Keep the watch near the iPhone while the installation completes.
3. Check the result
After both updates, open the iPhone’s Health app and check the Respiratory section for Blood Oxygen data. The update may roll out according to device and software conditions, so its absence does not automatically mean the watch is faulty.
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- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
- A GREAT FITNESS TRACKER—SE 3 can track your workouts in a healthy number of ways—from running and strength training to simply achieving your 10K steps a day. With real-time metrics and Workout Buddy powered by Apple Intelligence from your nearby iPhone,* you’ll hit your goals like never before.
- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- WOMEN’S HEALTH INSIGHTS—SE 3 has advanced sensors that track your wrist temperature while you sleep. With this smartwatch, you can log your periods and symptoms, get period predictions, and get notified of cycle deviations.*
- GREAT BATTERY LIFE AND FASTER CHARGING—Enjoy a smartwatch with all-day, 18-hour battery life* from sunup to sundown. Then charge up to twice as fast as SE 2* and get up to 8 hours of battery in just 15 minutes.*
If Blood Oxygen does not appear
Work through these checks:
- Confirm the model: The August 2025 restoration targeted certain U.S. Series 9, Series 10, and Ultra 2 units.
- Confirm the region: A watch bought outside the U.S. follows its own feature configuration; simply using it in the U.S. does not establish eligibility.
- Check both updates: Updating only the watch or only the iPhone may not be sufficient.
- Check the paired device: Make sure the updated iPhone is paired with the watch you are checking.
- Check Health: Look in Health’s Respiratory section rather than expecting the exact original on-watch presentation.
- Restart both devices: A restart can refresh the pairing and software state, though it is not a guaranteed fix.
- Contact Apple Support: If the model, region, pairing, and software versions appear eligible but the feature remains unavailable, Apple can verify the device configuration.
Managed, refurbished, imported, and second-hand watches can have configurations that are not obvious from the model name alone.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is the redesigned version as good as the original?
It restores the functionality without requiring an eligible owner to replace the watch, and it puts the resulting data back into Apple’s Health ecosystem. Those are significant advantages.
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The trade-off is convenience. The paired iPhone now has a central role in calculation and result presentation, making the experience different from the original implementation and potentially less useful when the phone is unavailable. The available reporting does not establish a new accuracy rating or prove that the redesigned version is medically equivalent to a clinical pulse oximeter.
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![Apple Watch Series 11 [GPS 42mm] Smartwatch with Jet Black Aluminum Case with Black Sport Band - S/M. Sleep Score, Fitness Tracker, Health Monitoring, Always-On Display, Water Resistant](https://m.media-amazon.com/images/I/41s72HIk5TL._SL160_.jpg)
- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
What Blood Oxygen can—and cannot—tell you
Apple Watch Blood Oxygen is best treated as a wellness and trend-monitoring feature. Readings can be affected by fit, movement, skin contact, temperature, circulation, tattoos, and other conditions. Do not use a watch reading alone to diagnose hypoxemia, sleep apnea, respiratory illness, or another medical condition.
Concerning symptoms or persistently unusual readings warrant advice from a qualified medical professional. A fingertip pulse oximeter may be more appropriate for someone who wants occasional spot checks, while Apple Watch is more useful to readers who value wearable convenience and Health app history.
Buying a used or refurbished Apple Watch
If Blood Oxygen is important, do not assume that every Series 9, Series 10, or Ultra 2 has the same capability. Before buying, ask the seller to confirm:
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- whether Blood Oxygen was enabled, disabled, or restored on that individual unit;
- the current iPhone and watchOS versions;
- that Activation Lock has been removed;
- battery health and the return policy.
A screenshot showing Blood Oxygen data in the Health app is more useful than a listing title that merely says “Series 9” or “Ultra 2.” Apple’s refurbished store is another option, although availability and feature status should still be confirmed for the specific U.S. configuration.
The bottom line
Apple Watch Blood Oxygen did return in the U.S. on August 14, 2025, but only as a limited restoration. Certain U.S. Series 9, Series 10, and Ultra 2 watches sold without the feature can regain it through iOS 18.6.1 and watchOS 11.6.1. The watch supplies sensor data, while the paired iPhone calculates and displays the result in Health. It is not a universal return, not necessarily the same as the original experience, and not evidence that the wider Masimo dispute has permanently ended.
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