This study aims to determine the changes in the career barrier (CB) trajectory of South Korean school dropouts over time and to identify the number of groups that can be categorized according to CB trajectory. The study analyzed three years of panel data on school dropouts from the Korean National Youth Policy Institute, which comprises adolescents in middle (ages 12-14 years) and high (ages 14-17 years) school. A total of 656 adolescents participated and were composed of 385 men (58.7%) and 271 women (41.3%). We used the latent growth model and conducted latent class growth analysis to classify CB trajectories and logistic regression to identify the influencing factors. Specifically, 6.6%, 15.7%, 22.9%, and 54.9% of the participants were classified into four groups, namely, 'low level-increase,' 'low level-decrease,' 'high level-increase,' and 'middle level-maintained.' Self-esteem, parental attachment, life satisfaction, depression, and career search behavior significantly influenced the classification of the groups. Lastly, the study discussed the theoretical and clinical implications and limitations.