Research has shown a strong connection between birth weight and future outcomes. We ask how health problems after birth affect outcomes using data from public health insurance records for 50,000 children born between 1979 and 1987 in the Canadian province of Manitoba. We compare children to siblings born an average of three years apart. We find that health problems in early childhood are significant predictors of young adult outcomes. Early physical health problems are linked to outcomes primarily because they predict later health. Early mental health problems have additional predictive power even conditional on future health and health at birth. (Contains 10 tables and 13 footnotes.)