The country's second-biggest health insurer says cyber attackers infiltrated one of its IT systems and obtained personal information about current and former customers as well as employees covered by the insurer.
"The information accessed includes names, birthdays, social security numbers, street addresses, email addresses and employment information, including income data," wrote Anthem CEO Joe Swedish in a letter to the company's policyholders.
"No credit card information was compromised, nor is there evidence at this time that medical information such as claims, test results, or diagnostic codes were targeted or obtained," Swedish said.
About 80 million of Anthem's customers and employees are affected by the incursion which was discovered last week, according to The Wall Street Journal.
The FBI is investigating the attack, and Anthem says it has hired a cybersecurity firm to examine its systems and recommend solutions.
The company says it has established a dedicated website where members can access information, and a dedicated toll-free number that both current and former members can call if they have questions related to this incident. That number is: 877-263-7995.
Anthem offers Blue Cross Blue Shield plans in California, New York and other states, and is headquartered in Indianapolis.
One in nine Americans receives coverage for their medical care through Anthem's affiliated plans, according to a statement on its website.