Adolescence and young adulthood are unique developmental periods that present opportunities and challenges for improving health. Health at this age can affect health throughout the lifespan. This review has two aims: (1) to examine trends in key indicators in outcomes, behaviors, and health care over the past decade for U.S. adolescents and young adults; and (2) to compare U.S. adolescents and young adults on these indicators. The review also assesses sociodemographic differences in trends and current indicators. Guided by our aims, previous reviews, and national priorities, the present review identified 21 sources of nationally representative data to examine trends in 53 areas and comparisons of adolescents and young adults in 42 areas. Most health and health care indicators have changed little over the past decade. Encouraging exceptions were found for adolescents and young adults in unintentional injury, assault, and tobacco use, and, for adolescents, in sexual/reproductive health. Trends in violence and chronic disease and related behaviors were mixed. Review of current indicators demonstrates that young adulthood continues to entail greater risk and worse outcomes than adolescence. Young adults fared worse on about two-thirds of the indicators examined. Differences among sociodemographic subgroups persisted for both trends and current indicators.