This study examined the impact of cumulative toxic stress, type of toxic stress (recent vs. lifetime stress), and changes in toxic stress (increase or decrease) on incident type 2 diabetes (T2DM) and incident cardiovascular disease (CVD) in an aging population. Adults free of disease were followed in the 2006-2014 waves of the Health and Retirement Study (HRS) with biennial assessment of stress and disease diagnosis for both T2DM and CVD. Cumulative toxic stress was defined as the sum of 17 traumatic events experienced over the lifetime or recently (within 5 years). Change in stress was defined as an increase or decrease versus no change between initial and final stress scores. Stress-related differences in age at T2DM diagnosis and age at CVD diagnosis were estimated using Cox proportional hazards regression models.The T2DM analysis identified that 11.80% of 8656 participants developed T2DM over eight years. The adjusted risk of T2DM significantly increased in a dose-response fashion with experiencing stress events. The adjusted risk of developing T2DM was associated with an increase in recent stress (HR=1.43, 95% CI=1.18, 1.72), compared to no change over eight years. Increase nor decrease in lifetime stress was not associated with incident T2DM whereas decline in cumulative stress (HR=1.24, 95% CI = 1.05, 1.47) and recent stress (HR=1.50, 95% CI=1.23, 1.82) was associated with elevated risk of T2DM. The CVD analysis identified that 15.86% of 8350 participants developed CVD over eight years. The adjusted risk of CVD significantly increased in a dose-response fashion with stress events. The adjusted risk of developing CVD was associated with an increase in cumulative (HR= 1.26, 95% C =1.09, 1.46), recent (HR=1.21, 95% CI=1.01, 1.44), and lifetime (HR=1.30, 95% CI=1.12, 1.50) stress compared to no change over eight years. Decrease in each type of stress was not associated with incident CVD. Both cumulative toxic stress and change in toxic stress were associated with incident T2DM and incident CVD. Efforts should be made to reduce toxic stress, particularly in the long-term, to delay the onset of T2DM or CVD in U.S. adults.