Oct 24 (Reuters) - The February hack at UnitedHealth's ( UNH )

tech unit Change affected the personal information of

100 million people, the U.S. health department's website showed,

making it the largest healthcare data breach in the country.

UnitedHealth ( UNH ) has previously said that hackers potentially

stole a third of Americans' data in one of the worst hacks to

hit the U.S. healthcare sector. The company began notifying

affected patients in June.

UnitedHealth ( UNH ) did not immediately respond to a Reuters

request for comment.

The number of impacted people was posted on a list of data

breaches maintained by the U.S. Department of Health & Human

Services' office for civil rights.

A breach at the health insurer Anthem - now known as

Elevance Health - in 2015 impacted nearly 79 million

people in the U.S.

The Change unit was breached by a hacking group called

ALPHV, also known as "BlackCat." UnitedHealth ( UNH ) first reported the

breach on Feb. 21.

The breach caused widespread disruptions in claims

processing, impacting patients and providers across the country.

In June, UnitedHealth ( UNH ) issued a public notice about the

ransomware hack as part of its requirements to notify the

estimated one-third of the country whose private data may have

been exposed in the attack.

At the time, the company said that while it cannot confirm

the nature of data affected by the breach, it could include

health insurance member IDs, patient diagnoses, treatment

information and social security numbers, as well as billing

codes used by providers.

Earlier this month, the company forecast a business

disruption impact of $705 million this year from the hack that

caused massive payment and other disruptions across the U.S.

UnitedHealth ( UNH ) issued billions of dollars in loans to providers

affected by the hack and incurred costs related to notifying

customers of the breach.