Prof. Ullmann is a specialist in internal medicine. Before entering the German Bundestag in 2017, he was a university professor at the University Hospital of Würzburg.
During his time as a resident 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 field of HIV/AIDS. He trained as an infectiologist at Harvard Medical School. Prof. Ullmann is a board member of the Professional Association of German Internists (BDI).
Since joining the German Bundestag, Prof. Ullmann has been a member of the Committee on Health and, since 2022, health policy spokesman for the FDP parliamentary group. He is also Chairman of the Global Health Subcommittee.