At the end of the war Carl completed his studies, graduating with Gerty in 1920.
In 2004 both were designated a National Historic Chemical Landmark in recognition of their work that elucidated carbohydrate metabolism. In late 1914 the Cori family moved to Prague and Carl entered the medical school of Charles University in Prague. While studying there he met Gerty Theresa Radnitz.
He was drafted into the Austro-Hungarian Army and served in the ski corps, and later was transferred to the sanitary corps, for which he set up a laboratory in Trieste.
While Carl was in Graz, Gerty remained in Vienna. A year later Carl was offered a position at the State Institute for the Study of Malignant Diseases (now the Roswell Park Cancer Institute) in Buffalo, New York and the Cori"s moved to Buffalo.
In 1928, they became naturalized citizens of the United States. While at the Institute the Coris’ research focused on carbohydrate metabolism, leading to the definition of the Cori cycle in 1929.
In 1931 Carl accepted a position at the Washington University School of Medicine in Saint Louis, Missouri.
Carl joined as professor of pharmacology and in 1942 was made professor of biochemistry. In Saint Louis, the Cori"s continued their research on glycogen and glucose and began to describe glycogenolysis, identifying and synthesizing the important enzyme glycogen phosphorylase. He stayed on at Washington University until 1966, when he retired as chair of the biochemistry department.
He was appointed visiting professor of Biological Chemistry at Harvard University while maintaining a laboratory space at the Massachusetts General Hospital, where he pursued research in genetics.
From 1968 to 1983 he collaborated with noted geneticist Salomé Glüecksohn-Waelsch of the Albert Einstein College of Medicine in New York, until the 1980s when illness prevented him from continuing. In 1976 Carl received the Laurea honoris causa in Medicine from the University of Trieste.
Carl shares a star with Gerty on the Saint Louis Walk of Fame.
Cori was elected a Foreign Member of the Royal Society (ForMemRS) in 1950 and the Carl Cori Endowed Professorship at Washington University is named in his honor, currently held by Colin Nichols.