Apple vs. Masimo: Five-Year Patent War Shaping Apple Watch

Apple vs. Masimo: Inside the Five-Year Patent War Shaping the Future of Apple Watch

Updated: August 15, 2025

The fierce legal battle between Apple and Masimo over pulse oximetry technology has entered its fifth year, dramatically influencing the smartwatch industry and racking up enormous costs for both sides.

📅 How It All Began

In January 2020, Masimo and its subsidiary Cercacor accused Apple of stealing trade secrets and infringing on patents tied to light-based health monitoring technology. A year later, the dispute escalated to the U.S. International Trade Commission (ITC) over the alleged use of Masimo’s proprietary pulse oximetry tech in the Apple Watch Series 6.

⚖️ The Landmark ITC Ruling

By October 2023, the ITC sided with Masimo, ruling that several Apple Watch models—from Series 6 to Series 9—violated Masimo’s patents. This decision resulted in an import ban effective December 26, 2023, forcing Apple to halt sales during the crucial holiday season.

💡 Did you know? — The import ban applied only to U.S. sales, meaning international customers could still buy these models without any feature changes.

🛠 Apple’s Clever Workaround

Apple responded swiftly, shifting the blood oxygen data processing from the watch itself to the paired iPhone. This allowed them to bypass the specific patent claims while continuing to sell the devices in the U.S., thanks to a favorable U.S. Customs ruling.

💰 A Costly Courtroom War

Masimo’s legal spending jumped from $5.5 million in 2021 to a staggering $70 million in 2024, with an additional $43.7 million already spent in the first half of 2025. Meanwhile, Apple is appealing the ITC decision in the U.S. Court of Appeals, arguing Masimo failed to meet domestic industry requirements.

🔄 Role Reversal

In an unexpected twist, a Delaware jury ruled in October 2024 that Masimo’s own smartwatch infringed Apple’s design patents—adding yet another layer to this high-stakes legal battle.

🚀 What’s Next for Apple Watch?

As of mid-2025, Apple is gearing up for the launch of the Series 11 and Ultra 3 smartwatches. Rumors suggest new health monitoring features like blood pressure tracking could be included, potentially sparking the next chapter in this patent war.