ABSTRACT The Patient Reported Outcomes Measurement Core (Measurement Core) will support the Northwestern (NU) OAIC's education and research mission through innovations in primary care-based, patient-reported outcomes (PROs) assessment of older adults with MCC to align care with patient priorities, monitor function and quality of life. The Measurement Core, guided by our proposed NU Pepper Center's underlying conceptual framework that seeks enhancements to primary care services to deliver patient priorities-aligned care through scalable opportunities 1) for older adults with MCC and caregivers to share their values and preferences with their care team; and 2) the timely, routine assessment of PROs. We will do so by using our extensive, internationally-recognized expertise on PROs measurement, functional outcomes and experience-of-care measures. The specific aims for the Measurement Core are to: Aim 1 Provide measurement expertise for the Northwestern Pepper Center and serve as a resource to the Research Education Component for junior faculty seeking skills in measurement. Aim 2 Conduct a developmental project (DP) to build an individualized, patient-centered system for primary care settings to monitor patient-reported outcomes among older adults with MCC. Aim 3 Inform patient-based studies of MCC in primary care settings by leveraging an existing External Project (EP) on quality of life and multimorbidity in cancer and CKD patients. We will support Pepper Scholar Pilot/Exploratory Studies, collaborate with other Resource Cores (Design, Analytics) on aging-specific DPs and ongoing EPs, facilitate Information Dissemination and more generally serve as an aging research methodological support resource for Chicago and the national OAIC community (Aim 1). The Measurement and Design Cores will heavily interface to design a primary care-based, patient-centered system to leverage EHR-based PROs measurement among older adults with MCC (Aim 2). Older patients will be able to choose the PROs (e.g., pain, fatigue, nausea) that are the most important to them, allowing primary care clinicians to more effectively prioritize patients' concerns (Aim 3). Finally, two ongoing EPs will be leveraged to probe how symptom monitoring and rapid symptom management can better inform primary care management of medically complex, older adults with MCC. Our Core is well suited to provide ongoing mentorship, research support, broad scientific contributions, while offering measurement expertise to the entire national OAIC Network.