The chapters in this section represent special populations of adolescents and young adults (AYAs). The health needs for AYAs from special populations can be challenging. These special populations include AYAs from the military or from families who are involved in the military; foster care or the juvenile justice system; homeless youth; immigrant youth and American Indian (AI) and Alaskan Native (AN) AYAs. These AYAs need assistance in overcoming barriers resulting from socioeconomic, cultural, political status, and psychosocial circumstances. Information provided in preceding chapters serves as a foundation for the care of AYAs, whereas the following chapters are designed to give providers a more nuanced understanding of the daily challenges these unique populations may experience.

Some of the special populations represented in the following chapters are relatively small in number, but collectively, these groups represent a sizeable population. For example, recent estimates suggest the following:

Thus, these subgroups represent a wide range of differences in culture, geography, beliefs, politics, and physical characteristics, which will challenge those who care for these AYAs. Another group included in this section that has unique needs and systems of care is the large number of AYAs in college. As many as 24 million individuals in the United States are estimated to be enrolled in colleges and universities and that over half of these students will be between the ages of 14 and 24 years by 2020.