Any insurance is, essentially, a gamble. Someone (a company) with more money than us is prepared to gamble, offering a huge stake (the payout) against our small stake (the premium). The Insurer works out the probability of a payout and calculates the premium that they want so that they make a profit on hundreds of clients but offer attractive enough rates to attract business. If all the facts were known, the total premium would be equal to the expected payout plus some profit minus some factor due to the fact that they can invest your premiums for a while. In the future, in the case of health insurance, it will by possible to predict very accurately, by looking at personal genetic makeup, the likelihood of an individual making large claims for many conditions. This means that insurance will cost more and more for potentially less healthy people. Where can it end? One could argue that this is not 'fair'. The NHS doesn't do it that way. Instead, they run out of money and services dwindle for everyone when total contributions are not high enough. Everyone complains at the suggestion of increased taxes for health but at least the taxes would be (ideally) spread around in a more 'fair' way. Which do 'we' want? If I am a healthy person, I want the Private Medical Insurance model. If I am a potentially unhealthy person I want the NHS model. Taxes are, in general, a very mild sort of leveling mechanism. The richest remain the richest, despite paying more tax. Should a health tax maintain the hierarchy of health in the same way that other taxes maintains the hierarchy of wealth?