Cancer among Adolescents and Young Adults (AYAs) is particularly difficult because age-related developmental challenges of identity, relationships, and vocation may add to the burden of cancer. Compared to other age-groups, AYAs have poorer psychosocial outcomes. Among AYAs with advanced cancer, too many miss opportunities to express their hopes, worries and end-of-life preferences, translating to both patient and parent distress. A potential barrier to improving these experiences may be that AYAs have few opportunities to develop the personal resources needed to handle adversity and articulate their needs. We have previously described the “Promoting Resilience in Stress Management” (PRISM) intervention for AYAs with cancer. This manualized, brief intervention is delivered in 4, 30-60 minute, one-on-one sessions, followed by a family meeting. It targets skills in stress-management and mindfulness, goal-setting, positive reframing, and meaning-making. All of these skills are associated with improved patient well-being in other populations, and findings from a recent pilot randomized controlled trial among AYAs with newly diagnosed cancer suggest PRISM is associated with improved perceptions of resilience, lower psychological distress, and higher healthrelated quality of life (HRQOL). This application proposes to build on our prior experience and fill three critical knowledge gaps: (1) PRISM’s impact among AYAs with advanced (as opposed to early stage) cancer; (2) Associations between AYA-PRISM participation and parent outcomes; and, (3) Associations between PRISM skills and patient engagement in clinical decision-making. This funding opportunity seeks to test AYA-specific palliative care interventions designed to positively impact HRQOL. Thus, we propose a multi-site randomized controlled trial among N=144 AYAs (n=72 PRISM, n=72 Usual Care; ages 12-21) with the primary trial outcome of patient-reported HRQOL 3 months following enrollment. Secondary outcomes will include patientand parent-reported anxiety and depression, and family “palliative care activation” (advocacy on behalf of AYA’s hopes and worries, engagement in goals-of-care conversations, and utilization of formal palliative care and psychosocial services). We hypothesize that AYAs who receive PRISM and their parents will report higher HRQOL, lower anxiety/depression, and higher activation when compared to those who receive usual care. This application offers an opportunity to expand the body of knowledge regarding methodologically rigorous and evidence-based palliative care interventions and standards of care for AYAs with advanced cancer and their families. Ultimately, this research has the potential to reduce the burden of cancer in these vulnerable populations.