One of the most important things the Affordable Care Act was supposed to do was put an end to a practice called pre-existing condition exclusion. Before the law passed, health insurers could refuse to cover any medical services for a health condition a person already had when they joined that insurance plan, or they could prevent the person from joining the plan entirely. So, for example, if you had psoriasis, the company might say that you could be on their plan, but you'd have to pay for all your psoriasis medications out-of-pocket.
