OLYMPIA, Wash. (AP) — Washington state’s insurance commissioner announced Tuesday a multistate investigation into this winter’s cyberattack on Premera Blue Cross.

Insurance Commissioner Mike Kreidler said he plans to work with his counterparts in Alaska and Oregon to look into operations at Premera, which is based in Mountlake Terrace, Washington. The investigation will explore the cyberattack disclosed by Premera last week, in which hackers accessed the personal information of 11 million consumers, including 6 million in Washington, between last May and the exploit’s Jan. 29 discovery.

The scope of the investigation may also include the extent of the financial damage done, steps taken to prevent a future attack and other cybersecurity aspects of the attack, Kreidler said. No timeline was given for the investigation, which will involve on-site reviews of Premera’s books and activities. Additional states could join the investigation team as it explores how far the security breach affected other members of the “Blue Card” system, which is Premera’s national provider network.

In Alaska, where an estimated 700,000 insurance consumers were affected, including 80,000 current and former state employees, Gov. Bill Walker last week encouraged enrollment in the protection services Premera offered to victims.