ABSTRACT Older adults face some of life’s most complex and influential decisions, just as cognitive, social, and other resources decline. Poor decision making, particularly in financial and health matters, poses enormous public health and economic challenges. Financial fraud offers an alarming example; older adults are among the most vulnerable and lose >$35 billion to fraud annually. The reasons why remain unclear, however, as decision making is a relatively nascent focus of aging research. In 2010, we began a study of decision making in the Rush Memory and Aging Project, an ongoing longitudinal clinical-pathologic study of aging. In the first two cycles, we enrolled >1,300 older adults, all of whom undergo detailed annual assessments of financial and health decision making. We reported that decision making involves a complex interplay among diverse resources and that many older adults—including those who are cognitively intact—exhibit poor decision making and are highly susceptible to scams. We also reported that poor decision making is associated with an increased risk of adverse outcomes including dementia and mild cognitive impairment (MCI). Further, in compelling preliminary studies, we found that neuroimaging and neuropathologic markers of brain aging and Alzheimer’s disease and related disorders (AD/ADRDs) degrade decision making. Thus, poor decision making is a harbinger of adverse health outcomes and may be due in part to age-related alterations in neural integrity. The overall goal of the proposed continuation (R01AG033678) is to identify the risk factors, consequences, and neurobiologic bases of age-related change in decision making. Continued annual data collection is necessary to precisely quantify age-related change in financial and health decision making. We will identify risk factors for decline independent of cognition and examine important health and financial impacts including financial exploitation and strain, outcomes we will newly measure. We also will newly incorporate in vivo neuroimaging to expand our focus on the neural basis of age-related change in decision making and complement clinical-pathologic findings. This study offers an unprecedented opportunity to link longitudinal decision making, behavioral, and adverse outcome data with neuroimaging and neuropathologic markers of neural integrity and AD/ADRDs. This integrative approach will efficiently determine the risk factors, consequences, and neurobiologic bases of age-related change in decision making and identify modifiable targets to improve decision making, health, and financial outcomes in old age.