Approximately 100 million elderly will enter Medicare over the next 25 years. We consider the potential benefits of interventions that would reduce or eliminate the most important risk factors for disease and spending. Effective control of hypertension could reduce health care spending $890 billion for these cohorts while adding 75 million disability-adjusted life years (DALYs). Eliminating diabetes would add 90 million life-year equivalents at a cost of $2,761 per DALY. Reducing obesity back to levels seen in the 1980's would have little effect on mortality, but yields great improvements in morbidity (especially heart disease and diabetes) with a cost savings of over $1 trillion. Smoking cessation will have the smallest impact, adding 32 million DALYs at a cost of $9.045 per DALY. While smoking cessation reduces lung disease and lung cancer, but these are relatively low prevalence compared to the other diseases. Its impact on heart disease is negligible. The effects on overall social welfare are unknown, since we do not estimate the costs of these interventions, the costs of any behavioral modification, or the welfare loss due to providers from lower medical spending.