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.

UnitedHealth has revealed that 190 million Americans had their personal and healthcare data stolen in the Change Healthcare ransomware attack, nearly doubling the previously disclosed figure.

UnitedHealth Group (NYSE:UNH) disclosed a cyberattack on its tech unit last year, impacting the personal information of 190 million individuals, marking the largest healthcare data breach in U.S. history.

Updated tally at Change Healthcare, owned by the Eden Prairie-based health care giant, nearly doubles the number of people affected by the massive data breach.

The cyberattack at UnitedHealth Group exposed personal information of 190 million people, leading to a $22 million ransom payment in bitcoin.

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