The authors identify and define key aspects of the progression from research on the efficacy of a new intervention to its dissemination. They highlight the role of transportability questions that arise in that progression and illustrate key conceptual and design features that differentiate efficacy, effectiveness, and dissemination research. An ongoing study of the transportability of multisystemic therapy is used to illustrate independent and interdependent aspects of effectiveness, transportability, and dissemination studies. Variables relevant to the progression from treatment efficacy to dissemination include features of the intervention itself as well as variables pertaining to the practitioner, client, model of service delivery, organization, and service system. The authors provide examples of how some of these variables are relevant to the transportability of different types of interventions. They also discuss sample research questions, study designs, and challenges to be anticipated in the arena of transportability research.