Project Summary Adolescents with asthma are at increased risk of adverse health outcomes related to asthma and are a group that is traditionally difficult to engage in self-management strategies for chronic illnesses. Smartphone use is prevalent and has been cited as a preferred method of communication among adolescents. The overall goal of the proposed project is to examine the effectiveness of a personalized, interactive asthma smartphone application in reducing asthma morbidity among adolescents who are at increased risk for future asthma exacerbations. Further, we will examine the impact of sharing smartphone asthma-related data with the primary care provider (PCP) on outcomes. To address this goal, we propose to conduct a 3-arm randomized, controlled trial with 432 at risk adolescents, ages 12-20 years, with uncontrolled, persistent asthma, to test the effectiveness of a mHealth Asthma Action Plan (mAAP) application that provides real-time, personalized feedback, asthma education, and data logging/tracking capabilities with and without PCP data sharing. The 3 groups will include: 1) a group utilizing the mAAP alone, 2) a group utilizing the mAAP with PCP data sharing (mAAP- DS), and 3) a usual care (UC) group that will utilize a smartphone application with daily non-asthma-related reminders (attention control). We will examine the application’s effectiveness compared to UC. The UC group will receive a simple mobile health application that will deliver daily reminders to eat fruits and vegetables via push notification. With the proposed mAAP, adolescents with asthma will have an individualized AAP readily available in a socially acceptable format (smartphone application) and will have the capability of utilizing the application at any time to guide asthma self-management. The mAAP will not only provide recommendations for steps to take during acute symptoms but will also reinforce daily medication adherence by sending medication and prescription refill reminders and reinforce asthma self-monitoring by sending prompts to record routine peak flow measurements and/or asthma symptoms. Further, data derived from the mAAP will be shared with participants in the mAAP-DS group and will allow investigators to measure the impact of data sharing on outcomes. We hypothesize that the mAAP will be an effective tool to reduce asthma-related morbidity among adolescents. This novel approach has high impact potential as it may be applicable to other age groups and patients with other chronic medical conditions.