Apple released iOS 18.6.1 (build number 22G90) on August 14, 2025, specifically targeting the restoration of Blood Oxygen functionality for U.S. Apple Watch Series 9, Series 10, and Ultra 2 users who’ve been without this feature since early 2024. The update represents Apple’s regulatory compliance solution following a U.S. International Trade Commission ban triggered by Masimo’s patent dispute.
This isn’t your typical iOS update. No new features, security patches, or bug fixes—just one targeted fix for a problem that shouldn’t have existed in the first place. The solution requires both iOS 18.6.1 and the companion watchOS 11.6.1 update to function.
How the New Blood Oxygen Experience Actually Works
Your watch collects data, but your iPhone does all the thinking and displaying.
As we reported earlier, he workaround shifts blood oxygen processing from your wrist to your pocket. Your Apple Watch still captures the sensor data, but everything gets shipped to your iPhone for calculation and storage. Results appear exclusively in the Health app’s Respiratory section—you won’t see readings directly on your watch anymore.
Apple describes this as providing “a new Blood Oxygen experience for users in the United States,” which translates to: we found a way around the patent ban by moving the computational heavy lifting. It’s functional, but clunkier than the seamless on-device experience international users still enjoy.
Who Gets This Update and Why It Matters
Only specific U.S. Apple Watch owners affected by the original trade ban qualify.
This update exclusively serves Apple Watch owners who bought Series 9, Series 10, or Ultra 2 models in the U.S. after the initial ITC ban removed Blood Oxygen functionality. If you purchased your watch before the dispute or bought it outside the U.S., you’re unaffected—your blood oxygen monitoring already works normally.
The restoration matters for users who paid full price for health tracking capabilities they couldn’t access. While the iPhone-dependent solution feels like a compromise rather than a victory, it beats having no blood oxygen monitoring at all.
You can grab both updates through your device settings. Just remember: this workaround represents Apple navigating patent law, not advancing health technology.
