Rowhani-Rahbar A, et al. - In view of the observed value of adolescent handgun carrying as a behavioral marker for youth interpersonal conflicts and an intervention point for violence prevention, researchers here sought to determine initiation age, cumulative prevalence, and longitudinal patterns of this behavior and on handgun-related norms and peer behavior among male and female rural adolescents. The control arm of the Community Youth Development Study, a community-randomized controlled trial of the Communities That Care prevention system, provided data for this work. Past-year handgun carrying was reported in 11.5% of males and 2.8% of females in Grade 6. 33.7% of males and 9.6% of females reported carrying handgun at least once between Grade 6 and age 19 years. Among participants who ever inscribed handgun carrying, 34.0% of males and 29.3% of females did so for the first time in Grade 6. Over the seven study assessments, 54.6% of males and 71.7% of females among participants who ever reported handgun carrying reported doing so only one time. Greater proportions of participants who reported handgun carrying than those who did not do so supported prohandgun norms and had a peer who carried among both males and females.