UnitedHealth's fourth-quarter revenue missed Wall Street expectations due to challenges in its health insurance business. The company's annual medical cost ratio, the percentage of premiums spent on medical care — rose to higher than anticipated. UnitedHealth faced significant challenges in 2024, including a cyberattack on its tech division and rising medical costs. The results follow the recent death of its insurance unit CEO, sparking discussions about frustrations with the U.S. health insurance system.