PROJECT SUMMARY Cardiovascular disease (CVD) is the leading cause of death for American women. While overall mortality from CVD has declined, event rates among younger women have increased dramatically in recent years. Cardiovascular health promoting interventions targeted at adolescent and young adult women are urgently needed to reverse this trend and halt the intergenerational transmission of CVD risk to future generations. The objective of the proposed research is to increase young women’s perceived susceptibility to CVD and provide a cue to action to adapt heart healthy behaviors. The aims of the proposed study are to 1) elicit information about necessary adaptations to an existing lifestyle-based CVD risk assessment tool and companion behavioral intervention from adolescent and young adult women and their primary health care providers using qualitative methods; 2) adapt the risk assessment tool and behavioral intervention into a single integrated mobile application using user-centered design principles; and 3) evaluate the usability and feasibility of delivering the mobile application with adolescent and young adult women presenting for wellness, mental health, and reproductive health visits in a pilot clinical trial. We will also examine preliminary outcomes from the initial trial, including changes in heart healthy behaviors and perceived risk for heart disease, in order to prepare for a larger clinical trial. Our long-term goal is to shift the paradigm of young women’s health care to include the prevention of CVD. By integrating this application into usual care, we aim to slow or arrest the cardiovascular health loss commonly seen as adolescent girls transition to young adulthood, thereby reducing CVD morbidity for this and future generations.