Margulies attended John Dewey High School in Brooklyn, New York, and graduated from Purchase College where he received a BFA in Visual Arts.

"[5] Long Lost opened Off-Broadway, produced by the Manhattan Theatre Club, at New York City Center — Stage I on May 14, 2019 in previews, officially on June 4.

It starred Laura Linney, Brian d'Arcy James, Eric Bogosian and Alicia Silverstone (later succeeded at the Cort by Christina Ricci), and was directed by Daniel Sullivan.

The play, set in the 19th Century, focuses on "Louis de Rougemont" who was shipwrecked on a Coral Sea Island and lived with Australian aborigines, or so he tells his listeners in England.

[14] The play made its world premiere in the September 2007 Pacific Playwrights Festival at South Coast Repertory, where it starred Gregory Itzin and was directed by Bart DeLorenzo.

[19] Dinner with Friends, which received the 2000 Pulitzer Prize for Drama,[23] was commissioned by Actors Theatre of Louisville (Kentucky), where it had its world premiere at the 1998 Humana Festival of New American Plays.

It went on to have a long run in Paris at the Comedie des Champs-Élysées, and productions in London, Berlin, Vienna, Stockholm, Tokyo, Mumbai, Seoul, Tel Aviv and Istanbul.

[31] Lavin had previously played the role of Ruth Steiner in May - June 1999 at the Geffen Playhouse in a production co-starring Samantha Mathis, directed by Gilbert Cates,[32] which was later re-produced for television broadcast by PBS Hollywood Presents in 2002.

The play has had many productions all over the country and around the world,[33] including one in London in 1999, at the Theatre Royal Haymarket, with Helen Mirren and Anne-Marie Duff, directed by Howard Davies.

It was directed by Michael Bloom and starred Dennis Boutsikaris, Deborah Hedwall, Jon DeVries and, in the supporting role of a German art critic, Laura Linney.

[38] The Loman Family Picnic was first produced by Manhattan Theatre Club (MTC) at City Center Stage II, from June 6, 1989 to July 2, 1989, with Marcia Jean Kurtz and Larry Block, directed by Barnet Kellman.

[41] The Model Apartment premiered at Los Angeles Theatre Center in November 1988, directed by Roberta Levitow featuring Chloe Webb as "Debby", Milton Selzer and Erica Yohn as her parents and Zero Hubbard.

Directed by Lisa Peterson, the cast featured Lynn Cohen (Lola), Akili Prince, Paul Stolarsky and Roberta Wallach.

was first produced Off-Broadway by the Manhattan Theatre Club Stage 73, from January 29, 1985 to February 23, 1985, directed by Claudia Weill and starring Madeline Kahn as Shirley.

[50] Found a Peanut was first produced by Joseph Papp at the New York Shakespeare Festival in June 1984, where it was directed by Claudia Weill and starred Robert Joy, Evan Handler, Peter McNicol, Greg Germann, Robin Bartlett, Nealla Spano, Kevin Geer and Jonathan Walker.

[51] Gifted Children was produced by the Jewish Repertory Theater (New York City) in December 1983, directed by Joan Vail Thorne and starring Dinah Manoff and Zohra Lampert.

[52] Luna Park is a one-act play inspired by the short story "In Dreams Begin Responsibilities" by Delmore Schwartz and was his New York debut as a playwright.

[56][57] Coney Island Christmas, adapted from the short story “The Loudest Voice” by Grace Paley, was commissioned and first produced by the Geffen Playhouse in November 2012.

[2] He has adapted a wide range of material for film and television, both fiction (including Middlesex by Jeffrey Eugenides, Tom Wolfe’s A Man in Full, The Touchstone by Edith Wharton) and non-fiction (notably American Lion: Andrew Jackson in the White House by Jon Meacham, The Most Dangerous Book: The Battle for James Joyce’s “Ulysses" by Kevin Birmingham, and biographies of David O. Selznick, Robert Capa and Keith Moon), all of which are unproduced.