In May 1938, the invasion of Austria by the Nazis forced Bibring and her family flee to London. While in London, Grete Bibring became a member of the British Psycho-Analytical Society. Edward Bibring was then invited to teach at Tufts University in Boston, Massachusetts. He accepted the position and, in 1941, Grete and Edward Bibring, along with their children George and Thomas, emigrated to America. Once in Boston, the two were among a group of "second generation" Freudian Scholars from overseas who popularized the concept of ego psychology in America. Bibring officially became an American citizen in 1946 and continued her work and research, establishing many positions, consultancies, and fellowship in a variety of institutions and organizations. In 1959, at the age of 64, her husband passed away of Parkinson's Disease. Bibring carried on in the field of psychoanalysis and continued to treat clients up to her death on August 10, 1977 in Cambridge, Massachusetts. She was 78.