As a board-certified behaviour analyst (BCBA), you work with a wide range of clients, particularly those with autism spectrum disorder (ASD). Some of these clients may not be verbal at all on one end of the spectrum, while some may have very advanced language skills on the other. For these clients and their families, you need a flexible and adaptable therapeutic framework to ensure the best behaviour outcomes. Drawn from relational frame theory (RFT)-the psychological theory of human language-acceptance and commitment therapy (ACT) can help. With this definitive professional manual, you'll learn to conceptualize your cases using ACT, create your own exercises, generate metaphors, be present with the unique individual learner in front of you, and practice the core ACT skills flexibly to ensure better behaviour outcomes for clients and their families. You'll find an overview of the theoretical connections between behaviour analysis, RFT, and ACT, as well as the core act skills, including present-moment awareness, flexible perspective taking, committed action, and values work. Finally, you'll find information on cultural competency and diversity to help you service a wide range of clients. If you're like many BCBAs, you need specialized resources when working with linguistically sophisticated clients, as well as their parents and caregivers. Let this book be your comprehensive guide to incorporating ACT into your work.