Abstract Breast cancer mortality rates and stage of diagnosis in Wisconsin continue to improve, but only for some. Using learnings from a statewide mammography project in Illinois, the Mammographic Quality Initiative (MQI) studies the mammographic process in Wisconsin to understand the factors that contribute to quality, create a shared measurement system to monitor and improve quality, and reduce disparities in early-stage diagnoses and breast cancer survival rates across the state. MQI is a project of the Community and Cancer Science Network (CCSN) at the Medical College of Wisconsin Cancer Center that brings together transdisciplinary teams made up of academic medicine and non-academic members to develop new research and action agendas to address disparities. Core to the CCSN transdisciplinary (TD) approach are three values–deep equity, systems thinking, and understanding of the issue from biology to policy. When CCSN TD teams come together and apply these values, new ways of seeing the problems that underpin disparities are surfaced and innovative solutions emerge. While building of shared measurement is not new, applying this approach to defining what gets measured, and applying it to mammography, is novel. MQI is using a multilevel model of transdisciplinary engagement. A statewide leadership team coordinates an initial study of mammographic quality and convenes regional learning collaboratives (RLCs) to examine quality and ways to improve. Its Southeastern WI RLC began meeting two years ago and is triangulating multiple sources of qualitative data, including lived experience, expert perspectives, and research, to help determine which factors should be included in a measurement of quality. MQI gathers data using multiple mediums to encourage sharing of knowledge and experiences, including facilitated meetings, literature reviews, surveys, community and survivor world cafes, and crowdsourcing. Learnings highlight that considering only one sector’s perspective results in an incomplete definition of quality and set of measures. Data shows that providers emphasize quantitative measures of the technical aspects of mammography, while navigators and patients emphasize systems conditions and justice orientations that shape the process. Existing definitions and measures of quality readily assess explicit practices, programs, and policies, but understanding additional factors—interpersonal interactions and power dynamics, and mental models around women in health care—offer opportunity to root deeper into causes and potential quality improvement solutions that have not yet been explored in mammography. The CCSN TD approach helps build empathy across perspectives, spotlights the contradictions inherent in provider and patient experiences, highlights enablers and barriers in the system itself, and importantly—lays bare when we are working at the surface, so that teams can dive deeper into solutions at semi-explicit and transformational levels of change (FSG Six Conditions of Systems Change). Citation Format: Kelly Hackett, Laura Pinsoneault, Tobi Cawthra, Bridgid Chanen, Tommi Thompson, Beth Brunner, Gale Johnson, Kristin Troy, Kara Gavin, Vaia Makris, Purushottam Laud, Melinda Stolley, Joan Neuner. A transdisciplinary approach to redefining mammographic quality to address disparities [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A131.