We outline here the essential elements of training for health care professionals who work with adolescent and young adult (AYA) patients with cancer. Research is emerging that a number of cancers manifest themselves differently in the AYA population, both in terms of biology and treatment response. In addition, there are a number of issues uniquely experienced by the AYA population that are critical for health care professionals working within AYA oncology (AYAO) to understand. The LIVESTRONG Young Adult Alliance, a Lance Armstrong Foundation program and a result of the Adolescent and Young Adult Oncology Progress Review Group cosponsored by the Lance Armstrong Foundation and the National Cancer Institute, assembled a group of experts representing relevant medical, psychosocial, and advocacy disciplines to create a blueprint for the training and development of health care professionals caring for AYA patients with cancer. The Alliance recommends that all health care professionals working in AYAO receive training that provides expertise in the following three critical areas: AYA-specific medical knowledge; care delivery specific to AYAs relative to pediatric and older adult populations; and competency in application and delivery of AYA-specific practical knowledge. These three areas should form the foundation for curricula and programs designed to train health care professionals caring for AYAO patients.