PROJECT ABSTRACT Approximately 1 million autistics will turn 18 in the next decade, many without the skills they need to achieve the quality-of-life that they and their families’ desire. Without effective supports, autistic youth struggle with daily living skills, regardless of their intellectual abilities. Daily living skills are fundamental to independence, paid employment, and better quality-of-life for autistic adults. Existing daily living skill interventions for this age group have only modest effects or show poor generalization to real world settings. Current treatments rely on explicit instruction of specific daily living skills (e.g., the steps for taking a shower), and they lack inclusion of mutable psychological factors that support the development and generalization of daily living skills. Treatments are further limited by inadequate knowledge of how social determinants of health (e.g., family income, community resources) contribute to daily living skills. Identification of mutable psychological factors and social determinants of health driving change in daily living skills for transition-age autistic youth is a vital to improving public health and social justice. This knowledge will identify pivotal intervention and service delivery targets for improving daily living skills. Better executive function and self-determination skills are associated with more advanced daily living skills, and both factors improve with treatment in autism. Our central scientific premise is that interventions for daily living skills, and the service delivery systems that promote them, will be enhanced with greater knowledge of psychological and systemic factors that directly impact these skills. Further, enhanced daily living skills will result in downstream improvements in quality-of-life and productivity. This project will address gaps in our knowledge with a prospective longitudinal study that evaluates psychological factors that drive change in daily living skills during the time when autistic youth exit high school (AIM 1), as well as the impact of daily living skills on quality-of-life (AIM 2). We will also explore the influence of both individual- (e.g., family income) and neighborhood-level (childhood opportunity index) factors on daily living skills (AIM 3). Finally, there is a general need for large representative samples (i.e., IQ range, speaking/nonspeaking, sex-assigned-at-birth, gender, race, ethnicity). The proposed longitudinal study will contain 3 visits (T1: baseline, T2: +1 yr., T3: +2 yrs.; final N=170). Our recruitment strategy will ensure all participants have at least one timepoint pre- and post-high school exit. We predict: AIM 1, H1) executive function and self-determination will explain significant variance in concurrent daily living skills above covariates; AIM 1, H2a,b) executive functioning and self-determination at baseline will predict daily living skills at T3 and change in daily living skills over time above covariates; AIM ...