Many interventions targeting cognitive skills or socioemotional skills and behaviors demonstrate initially promising but then quickly disappearing impacts. Our paper seeks to identify the key features of interventions, as well as the characteristics and environments of the children and adolescents who participate in them, that can be expected to sustain persistently beneficial program impacts. We describe three such processes: skill-building, foot-in-the-door and sustaining environments. We argue that skill-building interventions should target "trifecta" skills - ones that are malleable, fundamental, and would not have developed eventually in the absence of the intervention. Successful foot-in-the-door interventions equip a child with the right skills or capacities at the right time to avoid imminent risks (e.g., grade failure or teen drinking) or seize emerging opportunities (e.g., entry into honors classes). The sustaining environments perspective views high quality of environments subsequent to the completion of the intervention as crucial for sustaining early skill gains. These three perspectives generate both complementary and competing hypotheses regarding the nature, timing and targeting of interventions that generate enduring impacts.