What are the consequences of simply refusing to pay the bill? I know your credit rating would suffer and you will get many calls from collectors but are there m

What are the consequences of simply refusing to pay the bill? I know your credit rating would suffer and you will get many calls from collectors but are there more serious consequences? At least in California? For example, can the insurance or hospital refuse to give you care or cancel your policy? One of my friends did this after the insurance refused ambulance bills and while the experience was harrowing, just refusing to pay might just be how to deal with this.