In a plan set to be released Saturday, Mr. Sanders, the Vermont senator and presidential candidate, proposes wiping out an estimated $81 billion in existing debt and changing rules around debt collection and bankruptcy. He also calls for replacing the giant credit reporting agencies with a “public credit registry” that would ignore medical debt when calculating credit scores.

The proposals reflect Mr. Sanders’s concern that the medical system has placed financial hardships on too many Americans, by discouraging them from seeking needed medical care — but also by saddling them with expensive and unfair bills that can harm their financial security, ding their credit and, in some cases, lead to bankruptcy…

“We’re addressing it on both ends,” Mr. Sanders said. “We’re addressing it now by trying to help the people who have past due medical bills. And we’re addressing it by finally creating a health care system that guarantees coverage to people without any premiums, without any deductibles, without any out-of-pocket expenses.”