The healthcare giant filed a suit on February 20 in the US District Court for the Northern District of California, naming National Union Fire Insurance Company of Pittsburgh, Pa. (AIG), Federal Insurance Company (Chubb), Berkley National Insurance Company, Starr Indemnity & Liability Company, National Fire & Marine Insurance Company, RSUI Indemnity Company, Markel American Insurance Company, Fair American Select Insurance Company, and Allianz Global Risks US Insurance Company as defendants.