This is the first book devoted to the topic of validity assessment in rehabilitation contexts and is written by two board certified psychologists with extensive experience in clinical neuropsychology and rehabilitation psychology. This book describes (a) why validity assessment is important, (b) validity assessment methods, and (c) special topics related to validity assessment in rehabilitation psychology (e.g., managing invalid presentations, mild traumatic brain injury, forensic and disability applications, ethical considerations). Although primarily intended for the rehabilitation psychologist who is new to the topic of validity assessment, this book is also designed to be helpful to other rehabilitation specialists, students and trainees, and psychologists experienced in validity assessment, including neuropsychologists.