Researchers who conduct physical activity (PA) intervention studies provide an invaluable opportunity to further the prevention science knowledge base for implementing and delivering PA programs. Despite recommendations that screening is important to increase patient safety, the specific screening criteria best suited for different community applications are unknown. To add to the limited knowledge base, we examined the screening procedures and the occurrence of adverse events among more than 5,500 participants from 11 diverse PA interventions participating in a trans-National Institutes of Health (NIH) collaborative known as the Behavior Change Consortium (BCC). Numerous adverse events occur in sedentary, chronically ill, or older populations, although few are attributed to activity/exercise interventions. No serious study-related adverse events (SRAEs) were reported across different screening practices, interventions, and/or populations. Relatively few minor SRAEs were reported (primarily musculoskeletal injuries), emphasizing the need to be aware of potential musculoskeletal sequelae during exercise interventions. One common characteristic of these studies is that they recommended "start low and go slow" strategies, with moderate intensity PA as the goal behavior. Recommendations to reframe the meaning and use of screening criteria to initiate PA in the community are discussed. Although we were unable to conduct generalizable quantitative analyses from our data, the combined experience of the BCC studies provides a unique opportunity to examine PA-related screening and safety issues across diverse populations, settings, and intervention programs.