Background: This study is the first to examine the developmental course of high-intensity drinking (i.e., consuming 10+ drinks in a row) across late adolescence and the transition to adulthood. Methods: National longitudinal data (NÂ =Â 3,718) from Monitoring the Future were used to examine trajectories of 10+ high-intensity drinking from age 18 through 25/26 overall and across sociodemographic subgroups; results were compared with similar analysis of 5+ binge drinking trajectories. Results: Results document that 10+ drinkers consume not just a greater quantity of alcohol on a given drinking occasion, but also engage in 5+ drinking more frequently than drinkers who do not report having 10 or more drinks. Developmental patterns for 10+ and 5+ drinking were similar, with peak frequencies reported at age 21/22. Greater peaks in both 10+ and 5+ drinking were documented among men and among college attenders, compared with women and nonattenders, respectively. However, there was a steeper decline in 10+ drinking after age 21/22, indicating that risk for consumption of 10 or more drinks in a row is more clearly focused on the early 20s. Patterns of developmental change in both behaviors were driven largely by college students: No significant age-related change in 10+ drinking was observed among men and women who did not go to college, and no significant age-related change in 5+ drinking was observed among female nonattenders. Conclusions: Findings underscore the importance of recognizing high-intensity drinkers as a unique high-risk group, and that college attendance is associated with particularly strong peaks in the developmental course of high-intensity drinking.