Born Joyce Glassman to a Jewish family in Queens, New York, Joyce was raised on the Upper West Side of Manhattan, just around the corner from the apartment of William S. Burroughs and Joan Vollmer Burroughs. Allen Ginsberg and Kerouac were frequent visitors to Burroughs' apartment.

At the age of 13, Joyce rebelled against her controlling parents and began hanging out in Washington Square. She matriculated at Barnard College at 16, failing her graduation by one class. It was at Barnard that she became friends with Elise Cowen (briefly Allen Ginsberg's lover) who introduced her to the Beat circle. Ginsberg arranged for Glassman and Kerouac to meet on a blind date.

Joyce was married briefly to abstract painter James Johnson, who was killed in a motorcycle accident. From her second marriage to painter Peter Pinchbeck, which ended in divorce, came her son, Daniel Pinchbeck, also an author and co-founder of Open City literary magazine.

Since 1983 she has taught writing, primarily at Columbia University's MFA program, but also at the Breadloaf Writers Conference, the University of Vermont and New York University. In 1992 she received an NEA grant.