It is unclear when the breach occurred, Los Angeles Times reported.
“Cyber attackers executed a very sophisticated attack to gain unauthorized access to one of our parent company’s IT system and have obtained personal information relating to consumers and Anthem Blue Cross employees who are currently covered, or who have received coverage in the past,” Indianapolis-based Anthem said in a statement.
Hackers appear to have accessed customers' names, dates of birth, Social Security numbers, member ID numbers, addresses, phone numbers, email addresses and employment information, Anthem said.
At this point, it appears that the data stolen does not include medical files or credit card numbers, according to the company.
The company has established a website, www.anthemfacts.com, where members can access information about the situation.
There is also a dedicated toll-free number that current and former members can call if they have questions related to this incident: 877-263-7995.