PROJECT SUMMARY/ABSTRACT One in three Latinx report having extreme levels of stress and are more likely to say their stress has increased in the past year. Stress in Hispanics has been linked to high rates of depression, higher cardiovascular disease, and increased diabetes risk. High rates of stress and negative health outcomes among Latinx may be the result of the unique stressors (i.e., acculturative and discrimination) they encounter, which are not experienced by the general U.S. population. Indeed, acculturative stress and discrimination have been linked to poor health outcomes. Moreover, Latinas experience greater perceived stress and negative psychological outcomes compared to their male counters. Because Hispanic women have multiple social identities (e.g., race/ethnicity, gender, socioeconomic status) that interact with different forms of systemic oppression, this leads to higher levels of overall and cultural stress. Clearly defined gender-based roles are integral to Latinx cultural and contribute to both acculturative and discrimination-related stress. Both Cognitive-behavioral stress management interventions (CBSMi) and mindfulness meditation training have demonstrated success in reducing stress among Hispanics. However, Hispanics lack access to quality health care (including mental health services) and cultural values prevent them from seeking out services to address their mental health needs. One emerging accessible and cost-effective solution is mHealth, yet, there is a dearth of mHealth solutions that are developed specifically to address the stressors that Hispanics females face. Therefore, we aim to develop Quédate Tranquila, a mobile CBSMi (m-CBSMi) for Hispanic women. Quédate Tranquila will utilize theory (Transactional Model of Stress) to reduce affective, behavioral, and physiological responses to stress and its downstream health consequences among Latinas. The m-CBSMi will aim to foster and support healthy coping responses to stress by incorporating video testimonials, mobile tools that provide additional social support, and interactive pages that incorporate quizzes and activities. Community Action Corporation of South Texas will assist ISA in the recruitment of both healthcare service providers and end-users (Latinas). Eight healthcare service providers will be recruited for a focus group discussion to help shape the proposed intervention. Similarly, 32 Hispanic women will be recruited for predevelopment focus group discussions. When the Quédate Tranquila prototype is completed, the same 32 target end-users will return for a pilot test that includes usability testing. The usability test will include a series of tasks intended to highlight the different features of the proposed intervention. Three usability metrics will be assessed: efficiency, accuracy, and subjective satisfaction. Lastly, participants will review and rate (using a five- point scale) content satisfaction and intervention functionality of the prototype ...