We compared risk factor-adjusted mortality for California adults with developmental disabilities based on 22,576 adults receiving services in California, 1985-1994. Mortality rates were adjusted for factors such as age and level of functioning. Risk factor-adjusted mortality was 72% higher in community care than in institutions. The mortality pattern over the years 1993-1994, which had not previously been studied, was comparable to that of 1985-1992. The substantially increased risk in community care suggests that community settings may be less effective in preventing mortality in this population.