The U.S. Justice Department's National Institute of Justice (NIJ) funded the "environmental scan" in order to explore programs and legislation that address the developmental needs of justice-involved young adults. This effort was spurred by data that show young adults ages 18-24 account for a disproportionately high percentage of arrests and prison admissions, and about half of previously incarcerated young adults return to prison within 3 years following their release. Although most U.S. States set the legal transition for adolescence into adulthood at age 18, biological studies of brain maturation suggest that the ability to regulate emotions and control behaviors is not fully developed until about the mid-20s. In order to improve the criminal justice response to the developmental needs of youth adults, the scan incorporated a variety of methods to locate relevant programs and legislation. It identified 51 programs and eight pieces of legislation relevant to the criminal justice system's response to young adults. The scan found that formalized programs serving justice-involved young adults are diverse, jurisdiction-specific, and often dependent on local expertise and initiative. The scan also revealed gaps in services. There were limited examples of relevant legislation. Those identified focused on raising the age of juvenile court jurisdiction, increased discretion in sentencing, and expungement of records for justice-involved young adults. NIJ hosted a webinar on scan results for key stakeholders in September 2016. Future NIJ plans for addressing this issue are outlined.