Presents an obituary for Michael J. Kozak (1952-2019). He received his bachelor of arts in psychology in 1974 at the University of Pennsylvania. His research career began in his undergraduate years when he investigated reversing learned helplessness with Martin Seligman. His graduate studies were completed with Peter Lang at the University of Wisconsin-Madison. There, he investigated the psychophysiology of emotional imagery processing, guided by Lang's bioinformational theory of emotion. He earned his master of science in psychology in 1978 and his doctor of philosophy in clinical psychology with a minor in psychophysiology in 1982. His research and clinical efforts focused on improving the understanding, assessment, and treatment of a range of anxiety disorders, including posttraumatic stress disorder and obsessive-compulsive disorder (OCD). He also mentored and supported the career development of many developing professionals, from research assistants to postdoctoral fellows and psychiatry residents. One of his final research contributions, the cocreation of the Research Domain Criteria (RDoC), occurred during his time from 1999 to 2017 at the National Institute of Mental Health (NIMH). (PsycINFO Database Record (c) 2020 APA, all rights reserved).