Dozens of witnessed attested to dangerous conditions that Native Americans face in the healthcare system during a Senate hearing on Wednesday.
The U.S. has an agreement called the Indian Health Service dating back to 1787 that requires the federal government to provide American Indians with free health care on reservations.
But the service only has about half of the money it needs, and poor tribes in some of the most remote areas have underfunded facilities and substandard care, critics say.
"What we've found is simply horrifying and unacceptable. In my view, the information provided to this committee and witness first hand can be summed up in one word: malpractice," Wyoming Republican Senator John Barrasso, who chairs the Senate Committee on Indian Affairs.