Masimo sues US Customs over Apple Watch Blood Oxygen feature

Masimo has filed a lawsuit against U.S. Customs and Border Protection (CBP) over the reactivation of the Apple Watch’s Blood Oxygen feature.

The company is now seeking to reinstate the import ban on Apple Watch models that use the feature, claiming that CBP overstepped its authority and violated procedural rules. 

Masimo stated:

It has now come to light that CBP thereafter reversed itself without any meaningful justification, without any material change in circumstances, and without any notice to Masimo, let alone an opportunity for Masimo to be heard.

CBP changed its position on Apple’s watch-plus-iPhone redesign through an ex parte proceeding.

The company wants the original ITC import ban reinstated, arguing that each day the new ruling remains in effect causes irreparable harm to its competitive position in the U.S. market.

Masimo also states that CBP’s action nullifies the ITC’s exclusion order, which undermines the legal protection of its patented technology.

Specifically, on August 1, 2025, CBP issued an ex parte ruling permitting Apple to import devices that, when used with iPhones already in the United States, perform the same functionality that the ITC found to infringe Masimo’s patents.

Masimo said that was the first time it learned CBP had quietly reversed course two weeks earlier in an ex parte ruling, despite the agency’s policy that such decisions normally require both sides to be heard. 

Masimo only discovered this ruling on Thursday, August 14, 2025, when Apple publicly announced it would be reintroducing the pulse oximetry functionality through a software update.

Masimo asked the Washington court to halt the agency’s ruling and continue to block Apple from selling watches with the blood-oxygen feature.