This book provides an introduction for psychologists to screening, brief intervention, and referral to treatment (SBIRT), an evidence-based approach to identifying and treating substance use across a variety of behavioral health care settings and client populations. SBIRT has proven to be an efficient, cost effective way to identify harmful substance use and related problems and enhance individuals' motivation to change their behavior. Chapters present overviews of screening tools and approaches to brief intervention appropriate for diverse target populations; concrete steps for implementing SBIRT in a range of practice settings; and recommendations for training, advocacy, and policy. Psychologists who learn and implement SBIRT will be better equipped to meet the needs of their clients and help address the public health problem of substance use in this country. The aim of this book is to attend to psychologists' reluctance to address substance use with their clients. By engaging clients in proactive, open-minded conversations on this topic, providers can help lower the rates of harmful substance use.