A Senate Committee on Homeland Security and Governmental Affairs chairman wants the federal government to disclose how much money taxpayers lost because of the rapid-fire financial collapse of 12 Obamacare health insurance co-ops, The Daily Caller News Foundation has learned.

Sen. Ron Johnson demanded in a Jan. 19 letter to the Centers for Medicare and Medicaid Services (CMS) that federal officials provide full accounting for the losses. A part of the Department of Health and Human Services, CMS oversees the experimental co-op program.