Monitoring the Future is a landmark, federally supported research project that has tracked the substance use behaviors, attitudes, and values of U.S. adolescents and young adults for decades. Each year, tens of thousands of 8th, 10th, and 12th grade students, and follow-up samples of adults, are surveyed to monitor patterns in alcohol, tobacco, nicotine, and other drug use, as well as perceptions of risk and disapproval of use. The data provide nationally representative trend information that prevention professionals can use to inform needs assessments, set priorities, evaluate shifts in risk and protective factors, and tailor evidence-based prevention strategies to youth and community needs.