This randomized controlled trial will include Latino and Black adolescents with asthma ages 10-17 years old and their caregivers. Participants will be recruited from clinics in the Bronx, NY. The primary aims are to examine the efficacy of peak expiratory flow (PEF) prediction with feedback versus control feedback on 1) under-perception of asthma symptoms 2) controller medication adherence and 3) asthma control and emergency health care use. These aims will be examined across a 1-year follow-up. An exploratory aim examines the hypothesized pathway that the PEF intervention reduces under-perception of symptoms, shifts illness representations toward the professional model and increases adolescents' and parents' asthma management self-efficacy, resulting in greater medication adherence and improved asthma control.