U.S. government health plans spent more than $1 billion on Mylan NVs EpiPen emergency allergic reaction treatment between 2011 and 2015, according to figures released by the Centers for Medicare and Medicaid Services on Wednesday.

Mylan is under scrutiny for raising prices on the lifesaving EpiPen sixfold in less than a decade, making the devices unaffordable for a growing number of families. U.S. lawmakers and prosecutors are also investigating what impact Mylans EpiPen pricing has had on government-funded health programs.

CMS, in response to a request from U.S. Senator Amy Klobuchar of Minnesota, said in a letter that the Medicaid plan for the poor spent $797 million on EpiPen in the five-year period, including rebates provided by Mylan, or $960 million before rebates. Costs for the Medicare Part D program for the elderly was nearly $335 million, a figure that does not reflect rebates.