I have personal knowledge of a Children's Hospital taking the home of the parents of a 13 month old infant who received a liver transplant and had ran up at 3 million dollar bill in the hospital.
A little backstory -- I love to volunteer. Fire/EMS, STEM, Kids, you name it, if it's a cause that I support, I'll generally be there with a bell if I've got the free time. One of my non profits that I do a fair amount of technical and 'feel-good' work is a foundation that caters to small children who have terminal or other serious illnesses and helps their family out.
One night in 2013, a rather distraught woman came in saying that Children's had placed a lien on her home because of the unpaid medical bills; apparently, they had moved, civil service sucks in Ohio, and had a default judgement against them. New collections company comes in, finds this family, and then places a lien on her homes, car, and gets a court order to garnish their bank account.
Ultimately, it took a pro-bono attorney about 80 hours to get the entire mess cleaned up. Today, the little guy is almost 4 and the family has a clean title on their home and car, and as long as she keeps less than $2K in her checking account at all times and only has the one home and one car, Children's will never come after her for the money that is owed, and in 3 years, they'll wipe away the debt.