Everyone is required to buy themself basic health insurance, whereas the insurance companies must accept all comers and charge them the same rates. It's a neat setup, in my opinion. It accomplishes society-wide redistribution for basic health care--i.e., healthy people paying for unfortunate unhealthy people--while keeping the prices at a sane, self-funding level and avoiding the moral hazard of having governments promise ever-more benefits without figuring out how to pay for them.
But that's only the beginning. People are also legally required to have: