Evidence-based treatment and manualized psychotherapy have a recent but rich history. As interest and research have progressed, defining the role of treatment manuals in resident training and clinical practice has become more important. Although there is not a universal definition of treatment manual, most clinicians and researchers agree that treatment manuals are an essential piece of evidence-based therapy, and that despite several limitations, they offer advantages in training residents in psychotherapy. Requirements for resident training in psychotherapy have changed over the years, and treatment manuals offer a simple and straightforward way to meet training requirements. In a search limited to only depression, two treatment manuals emerged with the support of research regarding both clinical practice and resident training. In looking toward the future, it will be important for clinicians to remain updated on further advances in evidence based manualized treatment as a tool for training residents in psychotherapy, including recent developments in online and smartphone based treatments.