© 2018 American Journal of Preventive Medicine Introduction: Earlier development of cardiovascular disease risk factors in blacks versus whites may result from differences in maintaining health behaviors. Age-specific racial differences in maintaining health behaviors from ages 18 to 50 years were determined. Methods: In 1985–1986, the population-based Coronary Artery Risk Development in Young Adults study enrolled 5,115 participants aged 18–30 years. In 2017, a total of 2,485 blacks and 2,407 whites with one or more optimal health behaviors at baseline who attended one or more of seven follow-up exams over 25 years (i.e., through 2010–2011) were analyzed. The primary outcome, maintaining four or more optimal health behaviors, included BMI <25; never smoking; ≥150 minutes/week of moderate to vigorous physical activity; no/moderate alcohol intake (women/men: zero to seven/zero to 14 drinks per week); and Dietary Approaches to Stop Hypertension diet adherence score ≥15 (i.e., baseline highest quartile). Hazard ratios comparing blacks with whites for maintaining optimal health behaviors were calculated among participants with each optimal behavior at baseline. Results: From ages 18 to 50 years, 2.6% of blacks and 9.2% of whites maintained four or more optimal health behaviors (for optimal BMI: 16.0% and 30.1%, smoking status: 74.6% and 78.4%, physical activity: 17.7% and 21.4%, alcohol intake: 68.4% and 64.6%, diet adherence: 3.9% and 10.3%, respectively). The multivariable adjusted hazard ratio comparing blacks with whites was 0.63 (95% CI=0.56, 0.72) for maintaining four or more optimal health behaviors (for optimal BMI: 0.82 [95% CI=0.66, 1.01], smoking status: 0.57 [95% CI=0.52, 0.62], physical activity: 0.83 [95% CI=0.75, 0.91], alcohol intake: 1.19 [95% CI=1.03, 1.37], diet adherence: 0.71 [95% CI=0.61, 0.82]). Conclusions: Fewer blacks than whites maintained four or more optimal health behaviors until age 50 years, but maintenance was low among both races.