The Centers for Disease Control and Prevention's (CDC) Youth Risk Behavior Surveillance System (YRBS) has a long history of providing representative data on the nation's high school students. These assessments are crucial to CDC's mission of identifying health behaviors and experiences; understanding the determinants and co-occurrence of risks; and utilizing data to promote healthier and safer adolescence for the nation's youth through effective school and community programs, policies, and approaches. Although adolescents are in good health overall, clear risks remain. For example, while the proportion of high school students who are sexually active has steadily declined, half of the 20 million new STDs reported each year were among young people, between the ages of 15 and 24.2 Further, young people aged 13-24 account for 21% all new HIV diagnoses in the United States, with most occurring among 20-24 year olds. Although most high school students are increasingly making better decisions about their health, this report identifies subgroups who are at an increased risk for HIV, STDs, and teen pregnancy. The CDC looks forward to working with partners in public health and education to develop strategies to address the disparities highlighted in this report. Improving the health of adolescents and, subsequently, their health in adulthood will require our collective action at the family, school, and community levels. The CDC hopes this report will serve as a helpful resource to monitor its progress going forward.