Research examining sustainability of health promotion programs within organizational settings is limited. The Environmental Interventions in Residential Children's Homes (ENRICH) was a structural intervention that trained Wellness Teams (WTs) within residential children's homes (RCH) to target environmental changes that promote physical activity (PA) among residential youth. This study examines the sustainability of PA promoting environments and influences on sustainability within RCHs. A sustainability survey was administered to 14 RCHs 2 years after receiving ENRICH. Variables included sustainability of PA promoting environments, Organizational Influences, perceived organizational and individual benefits, and implementation of PA and general (i.e. Global) wellness activities. Activities reported as sustained and barriers were used descriptively to inform sustainability. Path analyses explained the relationship between sustainability influences and sustainability of PA promoting environments. Sustainability was found in 8 of 14 (57%) RCHs. Sustained activities reflected greater Global versus PA implementation. Global implementation mediated the relationship between Organizational Influences and sustainability, which may have been more easily achieved since Global activities were most likely controlled by WTs and did not require extensive organizational support from RCH administrators. Results highlight the importance of defining and assessing different implementation types when measuring sustainability and influences on sustainability within RCHs organizations.