HEALTHY AGING WAS ONCE thought to be a contradiction in terms. Enter James Fries, a professor of medicine at Stanford University School of Medicine. Early in his career, he foresaw a society in which the active and vital years of life would increase in length, the onset of morbidity would be postponed, and the total amount of lifetime disability would decrease. At the heart of his vision is an emphasis on improvements in preventive medicine and the untapped potential of health promotion and prevention. Known as “compression of morbidity,” Fries’ hypothesis holds that if the age at the onset of the first chronic infirmity can be postponed more rapidly than the age of death, then the lifetime illness burden may be compressed into a shorter period of time nearer to the age of death. Evidence supporting this hypothesis thus must take two forms: first, that it is possible to substantially delay the onset of infirmity; second, that the accompanying increases in longevity will be comparatively modest.1 Think about two points on a typical human lifespan, with the first point representing the time at which a person becomes chronically ill or disabled and the second point representing the time at which that person dies. Today, the time between those two points is about 20 years or so years. During the early portion of those years, chronic disease or disability is minor, but increases nearer to the end of life. The idea behind compression of morbidity is to squeeze or compress the time horizon between the onset of chronic illness or disability and the time in which a person dies. As Fries, the author of more than 300 articles, numerous book chapters, and 11 books, including Take Care of Yourself and Living Well, explained,2,3 By minimizing the number of years people suffer from chronic illness, we enable older people to live more successful, productive lives that benefit themselves and society. When we consider healthcare reform and new approaches to structuring health care systems, we must recognize that by avoiding long-term periods of morbidity, we reduce healthcare costs and improve the lives of patients at the same time. Since Fries’ seminal article on his hypothesis was published in The New England Journal of Medicine, compression of morbidity has been intensely discussed and argued for nearly three decades. Today, with data strongly confirming the hypothesis, compression of morbidity has become widely recognized as the dominant paradigm for healthy aging, at both individual and policy levels, and is thought to have laid the foundation for successful health promotion and programs. James Fries at Mount Everest Base Camp.