(CNN) Vermont Sen. Bernie Sanders has made it clear he wants to revolutionize health care by letting people see a doctor for no charge under his "Medicare for All" proposal. Now he wants to take their past-due medical bills off their hands, too.

It's the latest step in the 2020 Democratic candidate's quest to free consumers from what he describes as a "dysfunctional health care system" that ruins families' finances. The proposal, which is still in the works, would relieve consumers of an estimated $81 billion in medical debt and reform a 2005 federal bankruptcy law to make it easier to discharge such liabilities, according to Sanders' campaign.

It's widely accepted that medical debt is a problem, but Sanders has come under fire for some of his claims.

"500,000 people go bankrupt every year because they cannot pay their outrageous medical bills," Sanders told CNN's Brianna Keilar on State of the Union last month.

Sanders' statistic comes from a March editorial in the American Journal of Public Health written by David Himmelstein and Steffie Woolhandler, both doctors and longtime advocates of national, government-run health insurance system. They surveyed bankruptcy filers and found that two-thirds "very much agreed" or "somewhat agreed" that medical expenses or medical problems causing a loss of work contributed to their bankruptcy. That's equivalent to about 530,000 bankruptcies a year, the researchers said.

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