The first principle is that preventive interventions should focus both on reducing risk and enhancing protection. The second principle is that preventive interventions should target individuals exposed to higher levels of risk. The third principle is to address risk and protective factors at developmentally appropriate stages and whenever possible, intervene early. The fourth principle is to use data to select priority risk and protective factors in designated communities. The fifth principle is to select preventive interventions that have empirically demonstrated effectiveness to target the prioritized risk and protective factors. The accountability of where public dollars are being spent has significantly increased. Encouraging communities to implement programs that have demonstrated effectiveness increases the likelihood that money will be spent on programs that will reach the intended goal of reducing adolescent problem behaviors such as delinquency. More and more agencies are adopting an empirically supported menu-driven approach to intervention selection. The challenge to prevention scientists and community programs is to ensure that research be conducted to provide the needed empirical support for promising programs. Prevention science offers this set of principles to assist communities in allocating resources towards maximizing its prevention efforts.