Outcome measures for embedded pragmatic clinical trials (ePCTs) should reflect the lived experience of people living with dementia (PLWD) and their caregivers, yet patient- and caregiver-reported outcomes (PCROs) are rarely available in large clinical and administrative data sources. Although pragmatic methods may lead to use of existing administrative data rather than new data collected directly from PLWD, interventions are truly impactful only when they change outcomes prioritized by PLWD and their caregivers. The Patient- and Caregiver-Reported Outcomes Core (PCRO Core) of the IMbedded Pragmatic Alzheimer's Disease (AD) and AD-Related Dementias Clinical Trials (IMPACT) Collaboratory aims to promote optimal use of outcomes relevant to PLWD and their caregivers in pragmatic trials. The PCRO Core will address key scientific challenges limiting outcome measurement, such as gaps in existing measures, methodologic constraints, and burdensome data capture. PCRO Core investigators will create a searchable library of AD/AD-related dementias (ADRD) clinical outcome measures, including measures in existing data sources with potential for AD/ADRD ePCTs, and will support best practices in measure development, including pragmatic adaptation of PCROs. Working together with other Cores and Teams within the IMPACT Collaboratory, the PCRO Core will support investigators to select from existing outcome measures, and to innovate in methods for measurement and data capture. In the future, the work of the IMPACT Collaboratory may galvanize broader embedded use of outcomes that matter to PLWD and their care partners in large health systems. J Am Geriatr Soc 68:S55-S61, 2020.