Project Summary Mexican American children are the only demographic group whose asthma prevalence is increasing and Mexican American children with asthma have a ~2-3-fold greater risk of being hospitalized than their non- Latinx white counterparts. This excess burden of morbidity affects the ~ 200,000 Mexican American children with asthma in Texas. Thus, we propose to develop and pilot a scalable, culturally-tailored, multilayered asthma intervention, Asma Guardián, designed to reduce asthma morbidity among Mexican American children. Asma Guardián will be modeled on efficacious community-based asthma interventions and will include three “tool kits”: (1) support for accessing asthma specialist care, (2) asthma management education and support, and (3) home environment education, access to housing advocacy services, and access to environmental intervention supplies. Asma Guardián will be developed in partnership with Mexican American children with asthma and their parents and will be grounded in communication and behavioral science to maximize engagement. The primary objectives of the project are 1) To develop Asma Guardián, a culturally- tailored asthma intervention that facilitates access to asthma specialist care and provides education and support for asthma self-management and home environmental interventions and 2) To conduct a pilot trial to inform the planning of a state-wide trial of Asma Guardián. The proposed work is both necessary and sufficient to inform the planning of a state-wide trial of Asma Guardián, which will be the first scalable, culturally-tailored asthma intervention for Mexican American children and will serve as a model for delivering a population-scale intervention.