On the order of hundreds of thousands to over a million dollars without insurance, on order of $50k-$100k in copayments with insurance. Either way will wipe you out financially, effectively forcing you to go through medical bankruptcy and resetting any savings you have to $0. In addition, the equity in your house and car can also be seized, above some personal homestead exemption ($250k in New York for example, where the average house price is $2M, and $5k for vehicle). Not sure if they kick you out of the house immediately, or put a lien on it that comes due when you die/move out and house is sold. The only savings that are safe from bankruptcy are retirement savings in IRA and future social security payments.