Even Insured Can Face Crushing Medical Debt, Study FindsRandy Farris, 58, a factory worker from Conger, Minn., needed a knee replacement three years ago. His insurance covered 80 percent of the bill, but he needed to cash in an I.R.A. to pay his $4,000 share. “I haven’t been to the doctor since because I don’t want any more doctor bills,” he said.