Born on January 2, 1963 in Los Angeles, USA; Roman Catholic; married; two children. His childhood spent Ullmann in Los Angeles until he moved in 1972 with his family back to Germany. After graduating from the Reichenbach High School in Ennepetal in 1981, he studied human medicine at the Ruhr University Bochum and graduated in 1987 with the medical state examination. During his time as an assistant physician at the University Hospital at St. Josef Hospital in Bochum, he participated in clinical training at St Clare's Hospital / Spellman Center in New York City in the area of HIV / AIDS. Since 1995 he worked at the University Clinic Mainz. He trained as an infectiologist at Harvard Medical School from 1996-1998. He habilitated in 2008 in the Mainz University Medical Center and followed in 2012 a call to university professor at the University Hospital Würzburg. Ullmann is section spokesman for infectiology at the BDI (professional association of German internists) and assessor in the working group infections in hematology and oncology of the DGHO. Since 2015, he has been a lecturer at the Friedrich Naumann Foundation for Freedom.