ABSTRACT The overall goal of this five year R33 grant proposal, “Geriatric Oncology Research Infrastructure to Improve Clinical Care,” submitted on behalf of the Cancer and Aging Research Group (CARG; mycarg.org), is to further expand CARG’s national research infrastructure to support innovative investigators, leaders, and projects to answer significant interdisciplinary research questions at the aging and cancer interface. This proposal, in response to PAR 20-071, supports “advanced-stage development and utilization of novel research infrastructure to advance the science of aging in specific areas requiring interdisciplinary partnerships or collaborations.” Even after creating a robust aging and cancer research infrastructure over the last five years through the R21/33 mechanism, there remains substantial unmet need to expand this infrastructure to develop high-impact research at the aging and cancer interface. The overall goal remains to significantly and rapidly improve the lives of older adults with cancer through scholarship and leadership by expanding CARG’s impact. With the support of the R21/33 mechanism, the multiple Principal Investigators (MPI: Dale, Mohile, Hurria/Klepin) completed a coordinated, broad-based strategy to infuse aging principles into oncology research. Through the original grant’s Aims, CARG has become a recognized international leader for mentorship and scholarship in aging and cancer. CARG is a coalition of aging and cancer scholars dedicated to: 1) connecting interdisciplinary investigators together; 2) designing, implementing, and disseminating aging and cancer research; 3) mentoring new interdisciplinary investigators in the field; and 4) disseminating and advocating for equitable research and care for older adults. In exceeding the aims of the R21/R33 award, CARG successfully transitioned from infrastructure development (R21) to establishment (R33), centering around six Cores and a Leadership Team. This R33 renewal is sought to expand CARG’s impact through the following Aims: 1) Expand the reach of the infrastructure, using the Cores, to facilitate the design and rigor of CARG’s aging and cancer research; 2) Facilitate high-priority, impactful research at the interface of aging and cancer through pilot awards and the conduct of large, competitive multi-site studies; 3) Identify, cultivate, and mentor CARG investigators for leadership in aging and cancer research to develop the next generation of leaders in the field; 4) Build greater capacity for engagement with older patients with cancer and caregivers through CARG’s patient advocacy group (SCOREboard) to further grow patient-centered aging and cancer research; and 5) Develop and disseminate geriatric oncology-specific content including best clinical practices, research findings, and opportunities for collaboration and advocacy through a robust communication strategy. Ultimately, the proposed activities will substantially expand CARG’s infrastructure to advance h...