PROJECT SUMMARY/ABSTRACT The success rate of smoking cessation without any form of assistance is less than 10%, and rates are even lower among African American (AA) smokers (3.3%), who suffer worse health consequences. Therefore, it is critical to have interventions that particularly take AA smokers’ needs into account. Mobile health (mHealth) technology, a growing area of healthcare, shows promise in smoking cessation, and can be used to augment traditional smoking cessation treatment options such as pharmacotherapy or counseling. However, studies on culturally adapted mHealth interventions for AA smokers are lacking. More research is needed to determine how to make mHealth interventions more appealing to users and increase uptake by culturally adapting features such as contents type and delivery, design features, and other engaging elements. The goal of the proposed project is to develop the prototype of a mHealth application (app) for smoking cessation with features that are culturally adapted for AA smokers. The project will be successfully conducted under two aims: 1) Determine optimal content and design features of mHealth apps for smoking cessation are most preferred by adult AA smokers. I will develop and refine a list of preferred mHealth content and design features from the literature through focus groups with AA smokers. I will use feedback from the focus groups to conduct a discrete choice experiment (DCE) with hypothetical apps created with preferred content and design features to further refine the list based on level of importance. 2.) Apply user-centered design to develop a prototype of a mHealth app with content and design features rated as most preferred by AA smokers, followed by formative evaluation by end-users to ultimately develop final design specifications. I will develop the prototype (revisable version) of the mHealth app using a prototyping software. I will then conduct formative evaluation to evaluate workflow, user experience and perceived usability in an iterative manner with revisions and then create a set of documents with page for all components of the app and flowcharts which will be used to communicate with developers for the final product. The proposed research and training will propel me toward my career goal of becoming an independent scientist mHealth interventions, with a focus on health equity by developing expertise in nicotine addiction and cessation science, experimental designs such as discrete choice methodology, user-centered design with cultural adaptation and the development of mHealth interventions for AA smokers. This proposal is responsive to NIDA’s commitment to health equity and to developing new treatments for substance use disorders. Findings from this study will prepare me to conduct a future large-scale randomized trial comparing the new mHealth app versus a generic app such as QuitGuide.