In 2017, BJC HealthCare estimated $77 million of its $134 million in bad debt was owed by patients who probably would have qualified for free or discounted care. source
Nonprofit hospitals provide roughly $14 billion worth of charity care a year, about 2% of their operating costs. But their policies can have notable exemptions, such as excluding bills from doctors who are not on the hospital payrolls. source
According to a 2019 survey conducted by Cedar, 34% of respondents had a healthcare bill go to collections in the last year. The top reasons why include inability to pay the full amount (60%), confusion about bill amount (43%), and outdated billing and notification process (26%). source