To be effective in public policy formation, nurses must establish standards of care and advocate changes in financing and healthcare organization for persons who are not well served. The author delineates four areas (out-of-hospital prenatal and postnatal care; care of chronically mentally ill adults and severely emotionally disturbed youths; care for the elderly, especially in nursing homes; and care of the disabled and the chronically and terminally ill) where nurses should be the authority for much of the care provided. The author concludes that evolving dissatisfaction with the healthcare system means that nurses have the opportunity to make major contributions to the organization of all parts of the system, as it is ultimately put together, if they do the research and advocacy that is needed.