The most recent national surveys indicate that alcohol use disorders adversely affect the well-being, work productivity, financial welfare and families of at least 15 million Americans. Every year a very substantial proportion of the individuals who suffer from alcohol use disorder (AUD) attempt to stop drinking, but somewhere between 40 and 60% will relapse within the first three months. One of the most consistent correlates of early recovery is sleep problems. Importantly, these sleep problems constitute a major risk factor for relapse. While some efforts have been made to address this critical risk factor through targeted interventions, to date these efforts have been limited to small populations of patients and have yet to receive broad dissemination. HealthRhythms, Inc. (www.healthrhythms.com) was founded in 2014 with the goal of using mobile technology to add the layer of behavioral health care to all of healthcare. Our product model capitalizes on the ubiquity and intimacy of smartphones and their capacity to sense parameters of behavior that represent key indicators of behavioral health on a 24/7 basis that are captured in the user’s natural environment. We then build on that measurement to create highly personalized interventions for mental and addictive disorders with a particular focus on sleep/wake and rest/activity regulation. Through our initial SBIR funding, we have built and are currently validating Cue®, a mobile intervention app aimed at regularizing sleep/wake and other behavioral rhythms as a means of ameliorating symptoms of depression and anxiety. We now propose to adapt Cue® to the specific needs of individuals with AUD in early recovery who are experiencing difficulties with sleep. The product we envision will ultimately have three major components: 1) automatic behavioral monitoring via the sensors on the smartphone, 2) psychoeducation about sleep and the complex relationship between sleep and AUD and 3) personalized intervention based on the principles of cognitive behavioral treatment for insomnia (CBT-I) and built upon the individual user’s sensed behavioral profile. The Specific Aims of this Fast Track application are: PHASE I - Aim 1: Achieve a better understanding of the specific sleep difficulties experienced by individuals with AUD who are in the early recovery phase (the first six months of attempted abstinence). Aim 2: Based on the data obtained in these interviews, create a Beta version of the proposed intervention, tentatively called, CueToSleep. PHASE II - Aim 3: Beta test CueToSleep and, based on user feedback, prepare the final version of the app for an adequately-powered RCT. Aim 4: Test the efficacy of CueToSleep in comparison to monitoring alone in terms of its ability to improve sleep and diminish the risk of relapse and examine moderators and mediators of treatment outcome.