Premera Blue Cross , a health insurer based in the Pacific Northwest , said Tuesday that it was the victim of a cyberattack that could affect 11 million people . The company said hackers gained access to its systems on May 5 and that it did not discover the breach until Jan. 29 . The breach could have exposed members ' names , dates of birth , Social Security numbers , mailing and email addresses , phone numbers , member ID numbers and bank account information , the Mountlake Terrace , Washington , company said . Hacked : Premera Blue Cross said Tuesday its computer network had been hacked , potentially exposing data from 11 million people , in the second recent such attack on a major US health insurer . The information dates as far back as 2002 and affects users of Premera Blue Cross , Premera Blue Cross Blue Shield of Alaska , and Vivacity and Connection Insurance Solutions . Claims information , including clinical information as well as the personal information of people who did business with Premera , could also have been exposed . Premera said it has not found evidence that data was removed from its systems or that customer information has been used inappropriately . Premera said it was working with the FBI and the private security firm Mandiant 'to conduct a comprehensive investigation of the incident and to remove the infection created by the attack . ' 'The security of Premera 's members ' personal information remains a top priority . We at Premera take this issue seriously and sincerely regret the concern it may cause , ' said Premera chief executive Jeff Roe . Breach : The company admitted the breach could have exposed members ' names , dates of birth , social security numbers , addresses and more . 'As much as possible , we want to make this event our burden , not that of the affected individuals , by making services available today to help protect people 's information . ' It will provide two years of free credit monitoring and identity theft protection services to consumers affected by the breach . Premera currently has about 1.8 million members . It provides health , life , vision , dental , disability and other types of insurance . In February , Anthem , the second-largest health insurer in the U.S. , disclosed a breach that affected about 80 million customers . Cybersecurity experts say that attack was a sign that hackers are shifting their focus away from retailers and looking at targets in health care and other fields because their systems may be more easily breached . Companies ranging from retailers Target and Home Depot to Sony Pictures Entertainment have disclosed expensive and embarrassing data breaches recently . Last year , US retailer Home Depot said 53 million email addresses were stolen , months after fellow retailer Target said the personal data of 70 million customers was accessed . Analysts are now suggesting hackers could be moving away from retailers to companies like insurers , where sensitive data goes beyond the financial .
Premera Blue Cross , an insurer based in the Pacific Northwest , revealed the breach Tuesday . The ##urer claimed the breach could have exposed patients ' names , dates of birth , social security numbers , medications and more . Clinical documents including photographs and other medical history may also have been exposed .