Klebs received a medical degree from the University of Basel in 1896, then moved to the United States to practice medicine. Klebs worked with William Osler at Johns Hopkins University for a year after arriving in the U.S. and was a contemporary of William H. Welch. Following his work with Osler, he worked as a sanatorium director and tuberculosis specialist in Citronelle, Alabama and Chicago, Illinois. Given his long experience with the ailment, Klebs was named one of the first directors of the National Tuberculosis Institute.
