Childhood disruptive behaviors are highly prevalent and associated with adverse long-term social and economic outcomes. Trajectories of welfare receipt in early adulthood and the association of childhood behaviors with high welfare receipt trajectories have not been examined. Boys (n = 1000) from low socioeconomic backgrounds were assessed by kindergarten teachers for inattention, hyperactivity, aggression, opposition, and prosociality, and prospectively followed up for 30 years. Using group-based trajetory modeling of welfare receipt from age 19-36 years, we found that a unit increase in inattention (as measured at the age of 6 years old) was associated with an increased risk of receiving welfare. Nevertheless, we also found that Family Adversity was more strongly associated with trajectories for welfare receipt than any behavior. In sum, boys from disadvantaged backgrounds exhibiting high inattention in kindergarten are at elevated risk of chronic welfare receipt during adulthood. Screening and support for inattentive behaviors beginning in kindergarten could have long-term social and economic benefits for individuals and society.