Adolescents and Young Adults (AYAs) contribute approximately 1 million incident cases globally, but the great majority are underserved. In high-income countries, overall survival exceeds 80%, but the needs of this population during and after their treatment experience are poorly met, though specialized clinical programs are evolving. Engagement of national governments is advantageous and deployment of multidisciplinary teams essential. Collaboration between pediatric and adult healthcare providers is mandatory and AYAs must be given a strong voice in program development. Building and sharing international experience will hasten advances in clinical care, education, and research, while a focus on developing countries is a worthy challenge.