It's basically a gap health insurance plan that lets you keep your existing insurance after leaving a job -- except you have to pay the full price of your plan without an employer contribution (which is usually a pretty significant portion of the total cost), so it's pretty horribly expensive. But in some states you are required to have continuous insurance coverage or you get fined, so you're damned if you do, damned if you don't. Since most employers have a 60-90 day waiting period to join their insurance, most people end up having to get it for a few months even with a planned job change, unless they have a spouse who can add them to their policy.