Lower neural response to reward predicts subsequent depression during adolescence. Both pubertal development and biological sex have important effects on reward system development and depression during this period. However, relations among these variables across the transition from childhood to adolescence are not well characterized. Therefore, the current project utilized structural equation modeling to investigate the concurrent and prospective associations between depressive symptoms, neural reward responsiveness, pubertal status, and biological sex in a community-recruited sample at 9, 12, and 15 years of age. Findings indicate that there are bidirectional prospective effects between reward responsiveness and depression that emerge between ages 12 and 15. This may be a crucial time for studying bidirectional reward responsiveness–depression associations across time.