She was appointed by President Bill Clinton in 1996 at the recommendation of Senator Daniel Patrick Moynihan.
[citation needed] She was a Staff attorney of the Appellate Division of the Supreme Court of the State of New York, Mental Health Information Service from 1966 to 1968, and was then assistant corporation counsel with the Appeals Division of the New York City Law Department from 1968 to 1969, and from 1970 to 1972.
[3] She was a professor of law and political science at the University of California, San Diego from 1969 to 1970.
[3] In 1976, Gershon became a United States magistrate judge of the Southern District of New York, an office she would hold for twenty years.
She was confirmed by the United States Senate on July 30, 1996, and received her commission on August 1, 1996.