To date, most teen pregnancy prevention programs have been evaluated only once, often in small-scale efficacy trials involving the program developer. In recent years, however, a growing number of studies have sought to test how these programs perform when implemented on a broader scale, in different settings, or with different populations. These replication studies have the potential to greatly advance the field of teen pregnancy prevention research and help sustain the recent drop in teen birth rates in the United States. Achieving these goals, however, will require a careful interpretation and synthesis of study findings that avoids overly simplistic notions of replication “failure” and “success.” This research brief provides practical guidance for making sense of the growing body of replication studies in teen pregnancy prevention research. It is intended primarily for researchers, policymakers, and practitioners working in the field of teen pregnancy prevention research, to help them navigate and make the best use of findings from the growing number of replication studies.