The cyberattack at UnitedHealth Group's tech unit last year affected the personal information of 190 million people, the health conglomerate said on Friday, making it the largest healthcare data breach in the United States.

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 number of individuals confirmed to be affected by the data breach is almost double the company's previous estimate.

The cyberattack at UnitedHealth's tech unit Change affected the personal information of 190 million Americans, TechCrunch reported on Friday.

Last year's cyberattack against Change Healthcare affected nearly twice as many people as UnitedHealth Group previously reported.