There is no single definition of what constitutes a “serious illness,” but there is no doubt that it raises serious challenges for patients, loved ones, and providers. For the purposes of this discussion, we will consider the illnesses to which the Centers for Disease Control and Prevention (CDC) attributes the leading causes of death and disability: heart disease, cancer, chronic lung disease, stroke, Alzheimer’s Disease, diabetes and chronic kidney disease, which are leading cost drivers in the $3.5 trillion in annual U.S. health spending.