Umbarger grew up in Mansfield, Ohio and graduated from Mansfield Senior High School in 1939. At Ohio University he graduated with a bachelor's degree in chemistry in 1943 and a master's degree in zoology in 1944. For two years from 1944 to 1946 he served in the U.S. Navy as a hospital corpsman. In 1945 he served aboard the USS Rescue. In 1950 he received a Ph.D. in bacteriology from Harvard University. His doctoral thesis, supervised by J. Howard Mueller, is entitled Studies on the Interactions Involved in the Biosynthetic Mechanisms of Isoleucine and Valine in Escherichia Coli. From 1950 to 1959 Umbarger did research at Harvard. From 1957 to 1960 he was an assistant professor of bacteriology and Immunology at Harvard Medical School, but he was untenured. For the academic year 1959–1960, on leave of absence from Harvard, he worked at several laboratories in England. From 1960 to 1964 he held the appointment of Staff Investigator at the Cold Spring Harbor Laboratory. At Purdue University he was appointed in 1964 a full professor and in 1970 Wright Distinguished Professor of Biological Sciences. He held that professorship until his retirement.
