This practical manual presents an innovative modular treatment for adults and adolescents with a wide range of sleep and circadian rhythm problems, such as insomnia, daytime sleepiness, poor sleep quality, and irregular sleep-wake schedules. The treatment applies broadly to all individuals with sleep problems, including those with psychiatric disorders. It is grounded in a cutting-edge understanding of sleep health and integrates elements of cognitive-behavioral therapy for insomnia (CBT-I), interpersonal and social rhythm therapy (IPSRT), and other evidence-based therapies. Each module is described in detail, including specific practitioner guidance, sample scripts, developmental adaptations, and tips for enhancing motivation. Purchasers get access to a Web page where they can download and print the book’s 17 reproducible client handouts in a convenient 8 ½ x 11 size.