In 2007, the U.S. Department of Health and Human Services issued The Surgeon General's Call to Action to Prevent and Reduce Underage Drinking, a publication documenting a problem linked to nearly 5,000 injury deaths annually and poor academic performance, potential cognitive deficits, risky sexual behavior, physical and sexual assaults, and other substance use. This report reviews subsequent underage drinking and related traffic fatality trends and research on determinants, consequences, and prevention interventions. New research reports, meta-analyses, and systematic literature reviews were examined. Since the Call to Action, reductions in underage frequency of drinking, heavy drinking occasions, and alcohol-related traffic deaths that began in the 1980s when the drinking age nationally became 21 have continued. Knowledge regarding determinants and consequences, particularly the effects of early-onset drinking, parental alcohol provision, and cognitive effects, has expanded. Additional studies support associations between the legal drinking age of 21, zero tolerance laws, higher alcohol prices, and reduced drinking and related problems. New research suggests that use/lose laws, social host liability, internal possession laws, graduated licensing, and night driving restrictions reduce traffic deaths involving underage drinking drivers. Additional studies support the positive effects of individually oriented interventions, especially screening and brief motivational interventions, web and face-to-face social norms interventions, college web-based interventions, parental interventions, and multicomponent community interventions. Despite reductions in underage alcohol consumption and related traffic deaths, underage drinking remains an enduring problem. Continued research is warranted in minimally studied areas, such as prospective studies of alcohol and brain development, policy studies of use/lose laws, internal possession laws, social host liability, and parent-family interventions.