Recent behavioral and neuroscience research has found that young adults have more psychosocial similarities to children than to older adults. These findings on behavioral development should guide the justice system's response to young adults' criminal behavior. This paper proposes new institutional methods and processes for young-adult offenders ages 18-24. The principal recommendation is that the age of juvenile court jurisdiction be raised to at least 21 years old, with gradually diminishing protections for young adults up to age 24 or 25. In addition, such a system would recognize the diminished opportunities and greater demands that now face young adults, particularly those living in disadvantaged communities. For young-adult offenders, the corrections system must be used to promote work and family in the context of a broader government effort to promote order and predictability in poor communities. This implies that corrections programs for young adults should be primarily community-based, so that supervision and programming are conducted within the socioeconomic context of the community where the offenders must address the critical issues faced by young adults. The criminal justice system can facilitate prosocial development of young-adult offenders by using an age-sensitive risk assessment that recognizes the behavioral issues of young adults and their potential for change. Dynamic risk assessment instruments that measure behavioral change are recommended. Partnerships between the court and community organizations facilitate the rapid transition to programs that address identified risks and needs.