Jan 24 (Reuters) - The cyberattack at UnitedHealth

Group's ( UNH ) 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.

The hack at Change Healthcare affected the personal

information of 100 million people, the U.S. health department

had posted on its website in October.

The final number will be confirmed and filed with the U.S.

Department of Health and Human Services' office for civil rights

at a later date, the company said in an emailed statement.

The cyberattack disclosed in February at Change Healthcare

was perpetrated by hackers who identified themselves as the

"Blackcat" ransomware group, causing widespread disruptions in

claims processing and impacting patients and providers across

the country.

"Change Healthcare is not aware of any misuse of

individuals' information as a result of this incident and has

not seen electronic medical record databases appear in the data

during the analysis," the company said, adding that it has

provided individual or substitute notice to the "vast majority"

of those impacted.

The company issued a

public notice

about the ransomware hack in June last year as part of its

requirements under the Health Insurance Portability and

Accountability Act (HIPAA). HIPAA regulation requires companies

to notify patients of data exposures.

Information made vulnerable in the UnitedHealth ( UNH ) attack

is believed to include health insurance member IDs, patient

diagnoses, treatment information and social security numbers, as

well as billing codes used by providers.