The Ninth Circuit Court of Appeals affirmed a district court's summary judgment in favor of Apple Inc. in an antitrust lawsuit brought by medical technology company AliveCor, rejecting claims that Apple violated Section 2 of the Sherman Act through anticompetitive conduct related to Apple Watch heart rate monitoring technology.
The case, filed as *AliveCor, Inc. v. Apple Inc.* (9th Cir. 2026), centered on AliveCor's allegations that Apple monopolized the market for heart rhythm monitoring by strategically changing its Apple Watch algorithms to disable competing software. The three-judge panel, consisting of Circuit Judges Marsha S. Berzon, Michelle T. Friedland, and Salvador Mendoza Jr., issued its opinion on Jan. 8, 2026, with Judge Friedland writing for the court.
The dispute arose from AliveCor's development of SmartRhythm, a software feature designed to detect episodes of atrial fibrillation using data from the Apple Watch. SmartRhythm relied on heart rate data that Apple calculated using a specific algorithm while the Watch operated in "Workout Mode" setting. The technology represented AliveCor's attempt to leverage Apple's wearable device platform to provide medical-grade heart monitoring capabilities to consumers.
According to court documents, the competitive landscape shifted significantly after AliveCor launched SmartRhythm. The year following SmartRhythm's creation, Apple adopted a Watch operating system update that implemented a different algorithm to calculate heart rate data. This change had immediate implications for third-party developers like AliveCor who had built their applications around the original algorithm's data output.
Apple shared the new algorithm's data with third-party app developers but stopped providing access to the original algorithm's data that SmartRhythm required to function effectively. This change meant that SmartRhythm could no longer confidently detect atrial fibrillation episodes, essentially disabling the core functionality that AliveCor had developed.
Concurrent with these algorithm changes, Apple introduced its own competing feature called Irregular Rhythm Notification, designed to detect irregular heart rhythms. This Apple-developed feature used a third algorithm to calculate heart rate data, which Apple also made available to app developers. The timing of Apple's feature launch alongside the algorithm changes formed the basis of AliveCor's antitrust allegations.
AliveCor argued that Apple violated Section 2 of the Sherman Act by denying third-party app developers access to the original heart rate algorithm's data. The company alleged that Apple's conduct was specifically designed to disable software like SmartRhythm that would compete with Apple's own Irregular Rhythm Notification feature.
The Sherman Act's Section 2 prohibits monopolization and attempts to monopolize markets through anticompetitive conduct. To prevail on such claims, plaintiffs must typically demonstrate that a defendant has monopoly power in a relevant market and has engaged in anticompetitive conduct to maintain or extend that monopoly power.
The U.S. District Court for the Northern District of California, with District Judge Jeffrey S. White presiding, initially granted summary judgment in favor of Apple. The district court's ruling suggested that AliveCor had failed to establish the elements necessary for a successful Section 2 claim.
On appeal, the Ninth Circuit affirmed the district court's judgment, though the appellate panel reached its conclusion "on different grounds" than the lower court. While the full reasoning behind the Ninth Circuit's decision was not detailed in the summary portion of the opinion, the affirmance represents a complete victory for Apple in this antitrust dispute.
The case highlights ongoing tensions between platform owners and third-party developers in the rapidly evolving digital health technology sector. As major technology companies like Apple expand their health and medical device capabilities, questions arise about fair access to platform resources and data that third-party developers need to create competing applications.
The ruling also reflects broader challenges in antitrust enforcement in technology markets, where platform owners frequently update their systems and algorithms. Courts must balance legitimate business justifications for platform changes against claims that such changes constitute anticompetitive conduct designed to harm competitors.
For AliveCor, the decision represents a significant setback in its efforts to compete in the heart monitoring space using Apple's platform. The company had argued that Apple's conduct effectively eliminated its ability to provide competing atrial fibrillation detection services to Apple Watch users.
The case was argued and submitted to the Ninth Circuit on May 21, 2025, in San Francisco, California. The opinion's designation "FOR PUBLICATION" indicates that the decision will serve as binding precedent for future cases within the Ninth Circuit's jurisdiction.
This ruling may influence how courts evaluate similar claims involving platform owners' decisions to modify technical specifications or data access policies in ways that affect third-party competitors. The decision adds to the body of case law addressing the intersection of intellectual property rights, platform governance, and antitrust enforcement in technology markets.