My ex mother in law was a lazy, morbidly obese dependent of the state who received well over a million USD in care during the last 10 years of her life. Even when her moron of a husband cancelled their insurance policy she still managed to spend months in the critical ICU section of UC Irvine while they cut out a bread loaf-sized section of necrotic flesh and rebuilt her intestinal tract. They didn't, and couldn't, pay anything.

She received care, without insurance, for heart failure(including oxygen concentrator and tanks), a pulmonary embolism, and back pains(among other things which I can't fully recall and am actively trying to forget).

I'm not saying it happens to everyone, but it does happen.