Masimo has filed a new lawsuit against U.S. Customs and Border Protection (CBP) after the agency allowed Apple to restore the blood-oxygen monitoring feature on Apple Watch models in the United States. The dispute centers on whether Apple’s revised software design complies with an earlier import ban imposed by the U.S. International Trade Commission (ITC).
According to Bloomberg Law, the conflict escalated when CBP reversed its initial ruling without notifying Masimo, a move that enabled Apple to reintroduce the feature through a redesigned software approach. This has raised questions about due process and whether the agency overstepped its authority in changing its position.
The conflict between Masimo and Apple began when the ITC determined in late 2023 that Apple had infringed Masimo’s patents related to blood-oxygen sensing technology. This ruling forced Apple to disable the feature on Apple Watch Series 9 and Ultra 2 units sold in the U.S., while continuing to sell the devices without the functionality. Apple complied by issuing a software update that removed access to the feature for American buyers.
In early August 2025, CBP reversed its earlier decision and allowed Apple to reintroduce the tool. Apple subsequently rolled out a software change that shifts the calculations to a paired iPhone, with the watch collecting the raw data. This workaround restores the feature for users but changes how the results are processed and displayed. Apple argues that this approach respects the ITC’s exclusion order while maintaining access to a key health capability.
Masimo claims the reversal by CBP was unlawful. According to the company, the agency changed its position without notifying Masimo or giving it an opportunity to present objections. Masimo has described this as a violation of due process, arguing that CBP exceeded its authority and undermined the ITC’s ban. The company is now seeking a temporary restraining order and a preliminary injunction to block Apple from continuing to offer the restored feature in the U.S.
The timing of the decision has also been questioned. Masimo noted that Apple’s restored feature was announced shortly after the company publicized new U.S. investments in manufacturing and technology. While there is no direct evidence linking the two, Masimo suggests the policy shift could have been influenced by political or economic factors.
This case adds another layer to the ongoing legal battle between the two companies. Masimo has been a consistent challenger to Apple’s expansion into health technology, accusing it of misusing intellectual property. Apple has countered by framing its changes as innovative solutions that comply with existing restrictions. The outcome of this lawsuit could determine not only the future of the blood-oxygen feature on Apple Watch in the U.S., but also the boundaries of how companies can use software modifications to navigate patent disputes.
