Your medical data is not as safe as you think. Discover how a massive ransomware attack exposed millions and the key steps to protect your privacy now.

About 190 million Americans may have been affected by a cyberattack targeting UnitedHealth‘s subsidiary, Change Healthcare. The breach, which disrupted the company’s IT systems, resulted in the compromise of sensitive personal and medical information.

A cyberattack on UnitedHealth Group Inc. that paralyzed the US health-care system last year, snarling billions of dollars in payments for doctors and hospitals, also exposed sensitive data from 190 million Americans.

The updated tally extends the scope beyond what was previously described by company Chief Executive Andrew Witty.

UnitedHealthcare now estimates that 190 million people were impacted as a result of the cyberattack on its Change Healthcare unit last February— almost double previous estimates.

Over half of the U.S. had private data stolen in a 2024 cyberattack at the insurance giant—far more than previous estimates.

Large-scale attacks on health providers expose the data of millions of Americans each year. Consumers must remain vigilant, experts say.