Project Summary/Abstract Drinking problems and sleep problems each cause significant loss at individual and societal levels. Insomnia in particular is highly prevalent in patients with alcohol use disorder, is prospectively associated with the development of alcohol use disorder and contributes to poorer recovery prognosis following alcohol treatments. Insomnia, therefore, represents a modifiable risk factor for negative outcomes associated with alcohol use along the full continuum of alcohol use problems. Accordingly, the project proposes to improve sleep with an insomnia intervention tailored to individuals who meet widely accepted definitions for hazardous alcohol use as well as diagnostic criteria for insomnia disorder. This is a treatment development study that will adapt cognitive behavioral therapy for insomnia for adults engaged in hazardous use of alcohol. We propose an iterative approach to development, refinement, and preliminary examination of the utility of a telephone-delivered, 4-session version of cognitive behavioral therapy for insomnia adapted to hazardous alcohol users. The project will begin with a small, open label pilot to develop and refine procedures for administering the intervention. Then, we will conduct a small, randomized trial comparing the intervention to a sleep and alcohol education control condition. As this is a treatment development award, we will assess a number of intervention and study design feasibility domains in preparation for designing a larger study. We will also assess the effects of the intervention on alcohol use, sleep and mood by measuring these outcomes at baseline, post-treatment, and at 3- and 6-month follow up assessments. In sum, this proposal is the first step in a program of research that intends to use sleep as a lever to alter the course of hazardous alcohol use. Here, the first step is to adapt an already successful insomnia intervention to a unique population and conduct a preliminary test of that interventions’ acceptability to patients, fidelity by therapists, and effects on drinking, sleep and mood. If study results are promising, we will use these data and information gleaned about the study methods to pursue the next phase of research: designing and conducting a definitive study to test our insomnia intervention’s capacity to decrease alcohol use and modify the course of hazardous alcohol use.