The system for prevention planning using the tools of prevention science is Communities That Care (CTC). A collaborative U.S. project found 22 reliable and valid archival indicators of 12 major risk factors that predict rates of adolescent drug use at the county level. The project also developed a validated school survey that reliably measures risk, protection, delinquency, and drug use outcomes across States and ethnic groups. It allows a diagnosis of risk and protection levels in any geographical area, from a State to a neighborhood. With these tools, communities can organize to engage in outcome focused prevention planning, objectively assess their own profiles of risk and protection, and choose and implement effective strategies to address their unique strengths and needs. Communities trained to use the CTC system have improved inter-agency collaboration; reduced duplication of services; coordinated allocation of resources; and increased involvement of professionals, citizens, and youth in community prevention activities. Figures, references