Gewirtz received his Bachelor of Arts degree summa cum laude from Columbia University in 1967 and his Juris Doctor degree from Yale Law School in 1970. After graduation, he worked as a law clerk for the U.S. District Judge Marvin E. Frankel from 1970 to 1971, and as a law clerk for United States Supreme Court Justice Thurgood Marshall from 1971 to 1972. He was admitted to the bar in Washington, D.C., and was a lawyer at Wilmer Cutler & Pickering and then the Center for Law and Social Policy in Washington, D.C.
Gewirtz obtained his Bachelor of Arts degree summa cum laude from Columbia University in 1967 and his Juris Doctor degree from Yale Law School in 1970. Following graduation, he served as a law clerk for U.S. District Judge Marvin E. Frankel from 1970 to 1971, and then for United States Supreme Court Justice Thurgood Marshall from 1971 to 1972. He was admitted to the bar in Washington, D.C., and practiced law at Wilmer Cutler & Pickering and later at the Center for Law and Social Policy.