Over his 30-year career, Dr. Thomas Gratzer has established himself as a renowned figure in general and forensic psychiatry, predominantly serving the Twin Cities area in Minnesota. His extensive clinical involvement includes roles at significant healthcare facilities such as Psych Recovery, Regions Hospital, United Hospital, and Fairview University Medical Center. In these settings, he managed a substantial caseload of approximately 100 patient visits weekly and conducted numerous forensic evaluations.

Dr. Gratzer's prominent roles include his tenure as Senior Forensic Psychiatrist at the Minnesota Security Hospital from 1995 to 2002, where he distinguished himself through his dedication to complex forensic cases. Additionally, he served the Minnesota Department of Corrections as a consulting psychiatrist at the Juvenile Detention Center from 1999 to 2015, delivering critical psychiatric services to incarcerated youth. From 1995 to 2016, he also served as an attending psychiatrist at United Hospital, further solidifying his expertise in managing severe psychiatric disorders.

His leadership acumen was recognized with his appointment as the medical staff president at the St. Peter Regional Treatment Center in 1997, where he played a crucial role in shaping institutional policies.

He also made significant academic contributions as an Adjunct Assistant Professor in the Department of Psychiatry at the University of Minnesota Medical School from 2002 until 2021. He has taught a diverse student body, including medical students, psychiatry residents, and law students, at several institutions, such as the University of Manitoba and Rush-Presbyterian/St-Luke's Medical Center, enhancing his reputation as a committed educator.