Alzheimer’s Disease and Related Dementias (AD/ADRD) affect 15% of older US adults. Experiences in early life (e.g., differential exposure to childhood adversity) contribute to differences in AD/ADRD risk. Population distributions of these early life experiences, however, are themselves shaped by upstream factors that remain underexplored in the AD/ADRD literature. National, state, and local governmental investments in public goods, and which goods are prioritized, are one such set of intervenable upstream factors conditioning early life across place and time. For example, in 1965 the Elementary and Secondary Education Act facilitated intergovernmental grants (from federal to local governments via states) to enhance educational programing. By the 1980s, however, educational investments were outpaced by prison/jail expenditures. While upstream factors like governmental investments in early life could be linked to AD/ADRD risk and population distributions, and therefore serve as a lever for primary prevention, this has yet to be empirically tested. This K99/R00 leverages a novel longitudinal governmental spending database and two large, nationally representative, prospective datasets (National Longitudinal Survey of Youth 1979; US Health and Retirement Study) to estimate effects of federal, state, and local governmental investments in early life on midlife cognition and later life AD/ADRD risk. Triangulating across the strengths of confounder-control and quasi-experimental methods, this K99/R00 advances a nascent evidence base by (1) examining if county legal system or K-12 education investments in early life are independently associated with overall risk for, or differences in, midlife cognition and later life AD/ADRD; (2) characterizing how county legal system and K-12 education investments jointly co-vary over early life and evaluating if investment co-occurrence is associated with overall risk for, or differences in, midlife cognition and later life AD/ADRD; and (3) examining if early life exposure to federal policies monetarily investing in K-12 education affects overall, or differences in, midlife cognition and later life AD/ADRD. Under the guidance of an expert, multidisciplinary mentorship team, the accompanying training plan builds on the candidate’s subject matter and methodological background with additional skill building in the clinical/epidemiologic dimensions of AD/ADRD and its lifecourse determinants; database development; methods for characterizing longitudinal exposures; and quasi-experimental analysis methods. The proposed research aligns with several NIA strategic goals on identifying environmental and social factors in early life that create and sustain differences in cognitive function and AD/ADRD risk among older adults. Further, it initiates evaluation of early life governmental spending as an upstream driver of cognitive aging, develops a novel dataset – linkable to any individual outcome data – for future work, and is desig...