Siegmund Baum was born in Vienna as Siegmund Teutelbaum in 1920. He changed his family name to Baum in 1946. From 1930 to 1938 he attended the Realgymnasium, but due to the implementation of the discriminating Nuerenberg laws in Austria, in 1938, he was unable to obtain the Matura. In July 1938, he emigrated to Italy, where he was denied permission either to study or to work.
In 1939 Baum immigrated to the USA, where he started working in a factory. During WW2 he served in the US Army, from 1942 to 1945. In 1947, Baum was admitted as Associate in Arts at Los Angeles City College. From 1946 to 1950 he also attended UCLA (University of California, Los Angeles.) earning his BA in physiology in 1949, and his MA in 1950. From 1950 to 1960 he was physiologist at the US Naval Radiological Defense Laboratory, San Francisco. Concurrently, from 1954 to 1959, he attended the University of California at Berkley, where he received his Ph.D. From 1960 to1962 he was group leader of physiologists and radiologists at Douglas Missile and Space Systems. From 1962 Baum was a member of staff at the Armed Forces Radiobiological Research Institute, Bethesda, Maryland. From 1962 to 1964 he was head of the cellular radiobiological division, from 1964 to 1947 chairman of the experimental pathological department, and from 1976 chairman of experimental hematology department.
Concomitantly, he was professor at Uniformed Services at the University School of Medicine where he specialized in bio-medical productive research.
Baum was a member of the American Physiological Society; Radiation Research Society; Transplantation Society; International Society of Experimental Hematology; and Sigma Xi. Siegmund Baum received the 1st Annual Scientists Award from the US Naval Radiobiological Defense Laboratory (1960); and the Exceptional Civilian Service Award from the Defense Nuclear Agency (1973). Baum contributed many articles to professional scientific publications.