There is a need and opportunity to advance the science of de-implementation. Mammography screening among women 75 and older presents a robust area for inquiry related to de-implementation, as routine screening can lead to potential harms (e.g., overdiagnosis, overtreatment) while health benefits remain uncertain. Guided by de-implementation frameworks and methodological approaches from the field of implementation science, this presentation will discuss lessons learned and key findings from an online innovation tournament and discrete choice experiment to identify, select, and tailor de-implementation strategies at the patient, provider, and system levels for reducing mammography overuse in older women.