PURPOSE To understand trends, pathways, and experiences and to establish a framework for radiation oncology (RO) programs interested in developing global health (GH) initiatives. METHODS An in-depth interview was conducted of all US RO programs with established GH initiatives. Programs were identified by reviewing results of the 2018 Association of Residents in Radiation Oncology Global Health Resident Survey and individualized outreach to screen for additional programs meeting the following criteria: (1) active resident involvement in RO-specific GH opportunities, (2) active faculty involvement in these initiatives, and (3) department chair or program director awareness and support for ongoing opportunities. Among 88 residency programs, 11 were identified. Standardized questions explored the type of initiative, planning, staff and resident involvement, challenges, components to success, and history of programs through December 2018. RESULTS Between 2010 and 2018, 11 programs started initiatives. Total resident participants ranged from one to 13 (median = 3) in each program's history. Initiatives spanned education (n = 9 [82%]), clinical mentorship (73%), innovative technology (55%), bilateral hosting programs (45%), clinical development and equipment (45%), promotion of local research (36%), clinical care (36%), industry partnerships (27%), and remote tumor board (18%). Faculty involvement included radiation oncologists (91%), medical physicists (55%), and non-RO department faculty (27%). Six programs (55%) had faculty with prior GH experience. Four (36%) programs reported medical student involvement in projects. Barriers included international communication (36%), time for faculty (18%), funding (9%), and legal (9%) concerns. Commonest components of success included fostering relationships with international sites and identifying needs before solutions. CONCLUSION RO GH initiatives were reported as positive, educational, and feasible across 11 US residency programs. Growth is expected, representing opportunities for innovation and service among US programs.