SUMMARY/ABSTRACT The past decade in the US marked pivotal changes in the policy and retail environments regarding marijuana (MJ), the most commonly used federally illicit drug, particularly prevalent in young adults and racial and sexual/gender minorities (SGM). Despite controversy regarding recreational MJ, further legalization is likely, and states will continue to navigate its implementation. Thus, states with legalized recreational MJ provide an opportunity and a need to monitor recreational MJ retail and impact on various subgroups, as MJ regulatory frameworks are in their infancy and require advancements given the nuances of MJ retail (e.g., specialty stores, uniquely diverse products, progressive promotional strategies). The overall goal of this research is to inform regulatory efforts to minimize MJ use in vulnerable populations, in states with legalized recreational MJ and those that subsequently legalize it. The immediate objective of this proposal is to examine the recreational MJ market, MJ use, and related perceptions in consumer segments of disproportionately-impacted groups, particularly diverse young adults. Our scientific premise builds on literature indicating that licit drug retail marketing – both brick-and-mortar and online – target certain populations (e.g., racial/ethnic minorities, SGM, young adults) and the consequences of such marketing on substance use in these groups. The MJ retail has largely lacked standardized industry marketing surveillance tools, which have been critical in establishing the impact of tobacco and alcohol retail marketing and informing regulation. This proposal leverages our team’s prior work; we developed surveillance tools to characterize point-of-sale practices (e.g., age verification), product availability, promotional strategies, and product pricing at brick- and-mortar shops and online – now used broadly in research and practice. Findings indicated several issues with policy compliance (e.g., age verification), promotional strategies appealing to young people and minorities, various health claims, and minimal health warnings. Our team has also shown the utility of identifying young adults at high-risk for substance use and likely marketing exposure by using industry market segmentation based on psychographics (e.g., values, attitudes, lifestyle); the extent to which psychographics vs. sociodemographics inform industry marketing strategies, particularly among targeted populations, is not well known. Using a Socioecologic Framework and Diffusion of Innovations, we aim to: 1) determine whether neighborhood demography is associated with marketing and POS practices among recreational MJ retailers over time, accounting for policy context; and 2) compare young adult market segments defined by age and minority status vs. psychographics in relation to MJ use, perceptions, access, and advertising exposure in states with differing MJ policy contexts (recreational, medicinal, no legalized MJ policy) over ...