He is an MD-Psychiatrist who never practiced.
And lawyer.
Born in New York City and raised in Montreal, Krauthammer was educated at McGill University (B.A. 1970), Oxford University (Commonwealth Scholar in Politics) and Harvard (M.D. 1975). While serving as a resident and then chief resident in psychiatry at the Massachusetts General Hospital, he published scientific papers, including his co-discovery of a form of bipolar disease, that continue to be cited in the psychiatric literature.
In 1978, he quit medical practice, came to Washington to direct planning in psychiatric research in the Carter administration, and began contributing articles to The New Republic.