INDIANAPOLIS (AP) — The nation’s second-largest health insurer, Anthem, is contacting current and former customers after hackers got into its computer network and accessed personal information including Social Security numbers, incomes and street addresses.

Anthem is calling it a “very sophisticated” cyberattack. Anthem recently changed its name from WellPoint.

It runs Blue Cross Blue Shield plans in more than a dozen states.

Hackers infiltrated its computer network and accessed a swath of personal information about current and former customers including their incomes and street addresses.

The company says in a statement that it’s contacting customers affected by the “very sophisticated” cyberattack.

It also says that credit card information wasn’t compromised, and so far it hasn’t found any evidence that medical information such as insurance claims and test results was targeted or obtained.

Anthem says the FBI is investigating and it has hired Internet security company Mandiant to improve its network defenses.

Information stolen included names, birth dates, Social Security numbers, street addresses, email addresses and employment details including income.

The FBI urged Anthem customers contacted by the insurer to report suspected instances of identity theft.

[Associated Press]