Blue Cross Blue Shield of Michigan Mutual Insurance Co. was hit with an antitrust class action for allegedly weaponizing its "monopoly power" over the third-party market that covers catastrophic medical bills.

The named plaintiff, Wesco Inc., trustees of the Utility Workers Union of America National Health and Welfare Fund, self-funds the employee benefit plans through Blue Cross for administrative services, and uses stop-loss insurance to protect the employer from liability of unpredictable losses.