ABSTRACT Financial hardship (including financial stress, financial strain, asset depletion, and financial toxicity) is a highly relevant construct among the 5.7 million people with a diagnosis of Alzheimer’s disease and Alzheimer’s disease related dementias (ADRD) and their caregiving unit. In 2022, the total lifetime cost of care for a patient with ADRD was estimated at more than $400K with ~208K of which are borne out directly by the family of the person with ADRD— either through out-of-pocket health expenses, long-term care expenses or from the value of unpaid care. In addition, few families affected by ADRD have sufficient long-term care insurance or can afford to pay out-of-pocket for long-term care services for as long as the services are needed. There are also hidden costs incurred by families and caregivers including lost wages, terminated careers, responsibility of paying bills and expenses for their loved one with ADRD, and declining physical and mental health for the care provider as well as the care recipient. Yet, these economic estimates tell only part of the story; financial hardship also includes financial stress (the anxiety or psychological distress regarding expenses), financial strain (the objective lack of money to pay monthly bills), asset depletion (the impact on a persons’ life savings), and financial toxicity (the cost-associated reduction in health-related quality of life). While we know that the impact that financial hardship has on families can be astronomical, we know very little about how to quantify these difficulties or where to focus public health efforts to lessen these effects. To address this gap, we propose developing a new measurement system that can capture the multi-faceted aspects of financial hardship experienced by these families. Specifically, we will conduct semi-structured interviews with family members of people living with ADRD to identify the most impactful aspects of financial hardship. We will use this information, along with an in-depth scoping review and input from clinical and research experts, to develop a new case report form and new item pools. Next, we will employ a large-scale field-testing study (N=400 families of people with ADRD; a minimum of n=100 racial/ethnic minority families), to test the new item pools. State-of-the art statistical analysis methods will be used to identify the best items for the new financial hardship measures. This approach has the advantage of allowing the new measures to be administered as static long- forms, static short-forms, or as dynamic computer adaptive tests (CATs) or “smart tests” where items are selected based on a participant’s previous response. Ultimately, these new measures will advance the field by allowing us to characterize and prioritize the different aspects of financial hardship that are impacting these families, as well as identify those families that are at high risk for financial hardship and associated deleterious health and financial o...