Purpose of the provision
The Affordable Care Act prohibits health insurers from denying people coverage based on their medical history – for example, because they have a pre-existing condition or a family history of a particular ailment. However, insurers and lawmakers feared that this would produce a situation in which many people wouldn't buy health insurance at all – until they got sick. But to stay in business, a health insurance company needs to collect more money in premiums than it pays out in benefits, and that means healthy people have to buy insurance, too. That's where the individual shared responsibility provision comes in.