There is a specter haunting the American health care system. It is the prospect of widespread chronic illness and disability in an aging society. With it comes a daunting challenge to our health care delivery system, social welfare services, families, and communities. And it presents an equally difficult challenge to millions of us as individuals. For prolonged, slowly debilitating chronic illnesses will most likely be our companions in the twilight of our lives. At present, it is unclear whether the American health care and social service systems are prepared to cope with the challenges, both financial and ethical, that chronic illness poses to our society. Innovative policy ideas are needed, as are continuing research, extended and better coordinated social senvice programs, and educational programs that will equip health care providers to meet the special needs of persons with chronic illnesses.