Few studies have explored interventions to improve adolescent and young adult (AYA) cancer care delivery. While many AYAs receive cancer care at NCI Community Oncology Research Program (NCORP) sites, few enroll on clinical trials. Barriers and facilitators to pediatric oncologist activation of and enrollment on an AYA cross-network National Clinical Trials Network (NCTN) supportive care trial were assessed using a survey that was administered to 162 stakeholders representing all 47 children's oncology group (COG) institutions affiliated to an NCORP. Fifty-eight stakeholders participated representing 62% of all sites surveyed. Approximately half of participants (45%) were unaware of the trial. Seven sites had the study open and one enrolled a patient. Reasons for not opening and enrolling on the trial included limited research staff and resources, low anticipated accrual, and lower prioritization of the trial. Enrollment facilitators included having a local "AYA champion," improving communication between pediatric and medical oncology, and having site education on available AYA trials. Interventions focused on increasing site and provider awareness of AYA trials and decreasing local barriers to AYA enrollment are needed.