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. 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. 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]). Fewer blacks than whites maintained four or more optimal health behaviors until age 50 years, but maintenance was low among both races.