Abstract: Mobile health (mHealth) refers to the use of mobile devices in accessing and delivering healthcare services. The growing use of mobile phones worldwide along with increasing barriers to receiving quality healthcare is sparking tremendous interest in mHealth both in academia as well as in industry. However, to realize the true potential of mHealth, we need interdisciplinary collaborations between specialists in behavioral sciences, human-computer interaction, machine learning, and statistics. I will describe Just-in-time Adaptive Intervention (JITAI), a conceptual framework designed to facilitate interdisciplinary communication in mHealth. I will also highlight the role of reinforcement learning algorithms in personalizing mHealth interventions to suit the needs of individuals at particular moments in their daily lives.