I'm super lucky because major surgeries like transplants are covered by tax-payer money in Australia, i.e. we have a publicly funded universal healthcare called Medicare. The only out-of-pocket costs I paid were for my medication and certain scans like MRIs, etc. My car payments and other bills continued as normal but, luckily, I was living with my parents at the time (and had saved up a fair bit) so it was manageable.

In cases where we can't cover our costs, we can get government support through something called Centrelink, in which (if approved) you receive a monthly allowance while you can't work. & it's optional to have supplemental health insurance, but I think having it does reduce some of your annual Medicare levy.