On 17 March 2015, Premera Blue Cross announced that it was the target of a “sophisticated cyberattack” in which unauthorized users gained access to Premera’s IT systems andpotentially the data of 11 million individuals.  The initial attack is reported to have occurred on 5 May 2014 and was discovered by Premera only on 29 January 2015.

According to Premera’s statement, there is no evidence that information was removed from its systems or that any such information has been used inappropriately. However, Premera is providing affected individuals with free credit monitoring and identity theft protection services. Premera has reported that it is working with the FBI to investigate the cyberattack.
Premera published certain information about the breach in this FAQs page.