Aging of the population and lowered average age of retirement imply greatly increased public costs for pensions and health care in western societies. Prolongation of working life is necessary to counteract large budget deficits, and most western countries are now in the process of changing public retirement benefits. However, a prolongation must be accomplished without threatening the well-being of elderly persons, and therefore working life needs changes that accommodate the capacity and demands of an aging work force are needed. No scientific intervention studies have as yet demonstrated that early exits from working life can be prevented while work ability, health, productivity, and a high quality of life are maintained. However, several studies on return-to-work after prolonged sick leave, re-entry to work after lay-offs, risk factors for early retirement, risk/health factors for maintained work ability, and case studies provide indirect support for the feasibility of preventing early exits, Scientific studies comparing different approaches, and performed in varying cultural and environmental conditions, are needed.