Anne Kaufman Schneider, who shepherded the plays of her father, George S. Kaufman, a titan of 20th-century American theatrical wit, into the 21st century with an acerbic sagacity all her own, died on Thursday at her home in Manhattan. She was 99.

Her executor, Laurence Maslon, confirmed the death.

“Headstrong girls are difficult,” Ms. Kaufman Schneider once told The New York Times, “but that was the source of my good relationship with my father. And it started early. Because there wasn’t any baby talk. We went to the theater together starting when I was 4. Now I have made his work my agenda in life.”

George Kaufman’s stellar career as a hit-making playwright and stage director included two Pulitzer Prizes — one, in 1937, for “You Can’t Take It With You,” a comedy he created with his most constant collaborator, Moss Hart; the other, in 1932, for “Of Thee I Sing,” a satirical political musical he wrote with Morrie Ryskind to a score by George and Ira Gershwin.

Even so, after his death in 1961 at the age of 71, Kaufman was a hard sell for theatrical revivals.

“Very little happened at all,” Ms. Kaufman Schneider later recalled, “until Ellis Rabb revived ‘You Can’t Take It With You’ for the A.P.A./Phoenix Theater in 1965. Ellis proved that these are classic American plays.” (Founded by Mr. Rabb, an actor and director, the A.P.A., formally the Association of Producing Artists, was a Broadway entity notable for mounting revivals after it merged with the Phoenix Theater, another Broadway house.)

Ms. Kaufman Schneider proceeded to oversee her father’s renaissance over the next 50-plus years — a term of service that outdistanced his own living stewardship of his career.

She encouraged countless regional theater productions and helped steer two of them to Broadway: Mr. Rabb’s “You Can’t Take It With You,” which originated in Ann Arbor, Mich., and a revival of Kaufman and Edna Ferber’s “The Royal Family,” which was first presented at the McCarter Theater in Princeton, N.J., and reached Broadway in December 1975.

She also helped nurture a “Kaufmania” festival at Arena Stage in Washington, D.C., for her father’s centennial in 1989 and a major Lincoln Center revival of Kaufman and Ferber’s “Dinner at Eight” in 2002.

“The wisecracking woman who is smarter than all the men” was how Ms. Kaufman Schneider defined a classic Kaufman heroine. “Which in some ways is what I modeled myself after — I hope unconsciously. That’s the kind of woman he admired.”

She was born on June 23, 1925, and adopted three months later by Kaufman, then the drama editor of The New York Times, and his wife, Beatrice (Bakrow) Kaufman, who was known as Bea, a literary figure in her own right as an editor and tastemaker.

Kaufman had begun writing plays on the side in 1918, almost always with collaborators, particularly Marc Connelly, another future Pulitzer winner, who scripted five Broadway comedies with him in four years, including “Merton of the Movies” in 1922 and “Beggar on Horseback” in 1924. (Kaufman wrote only one play solo,: “The Butter and Egg Man,” which was also a hit, in 1925.)

A notoriously aloof germaphobe who washed his hands after any contact with another human being, Kaufman was hardly a likely candidate for fatherhood. His marriage to the conversely gregarious and vigorously social Bea Kaufman had become a loving but chaste one after she suffered an early miscarriage; both openly pursued extramarital affairs.

Into this odd family ménage entered Anne, who grew up at a remove from her parents, attentively raised instead by a succession of foreign-born governesses, nannies and maids, as biographies of Kaufman and interviews with Ms. Kaufman Schneider have attested.

Her mother called her Button and her father called her Poke, an eliding of “slow poke.” Her most regular family contact with them was in stagy “good nights” at their celebrity-studded dinner parties. Little Anne discovered that sharp exit quips made her father laugh with paternal pride.

On Sundays, the help’s day off, her mother handed her over to her father with an admonition: Do something with her. On his own, Kaufman mainly did two things, make theater and play cards, and he excelled at both. He took his daughter to his bridge club, where she stoically looked on, developing what would be a lifelong aversion to card games. He would also take her to the theater, where their deepest bond was born.

Anne attended five prestigious private schools in succession: Walden, Lincoln, Todhunter and Dalton in Manhattan and Holmquist in Pennsylvania, near the family’s country house. She largely grew up in a small apartment adjacent to their palatial home at 200 West 58th Street in Manhattan; her parents had acquired it just for her upbringing. She later lived with them in a series of elegant East Side addresses.

Admitted to the University of Chicago in 1943 at 18, she instead married a young New York Times reporter named John Booth. When, during World War II, he was shipped overseas as a soldier six months later, she moved back home with her parents; when Mr. Booth returned from military duty, she divorced him. She married Bruce Colen, a magazine editor, in 1947 and had a daughter, Beatrice, with him the next year before divorcing him, too.

In 1960, she married Irving Schneider, the general manager for the theatrical producer Irene Mayer Selznick. He had been an assistant stage manager on the original 1934 production of Kaufman and Hart’s play “Merrily We Roll Along” (later adapted by Stephen Sondheim as a musical). That marriage lasted until Mr. Schneider’s death in 1997.

After bonding with the stage actress Eva Le Gallienne during her starring run in the 1975 revival of “The Royal Family,” Ms. Kaufman Schneider became her devoted friend and constant companion until Ms. Le Gallienne’s death in 1991 at age 92.

Ms. Kaufman Schneider’s daughter, Beatrice Colen Cronin, died in 1999. Two grandsons survive.

Of all her father’s many collaborators — including Edna Ferber, Ring Lardner and John P. Marquand — Moss Hart was his favorite, Ms. Kaufman Schneider said. “I think they were very much mentor and apprentice, even father and son,” she said in a 1998 interview with The Times.

Ms. Kaufman Schneider first met Mr. Hart’s future wife, the singer, actress and later arts administrator Kitty Carlisle, on the set of the Marx Brothers movie “A Night at the Opera” (1935); Ms. Carlisle was co-starring in the film, which George Kaufman had co-written. The two women reconnected when Ms. Carlisle married Mr. Hart in 1946, becoming, in Ms. Kaufman Schneider’s words, “inseparable,” particularly after the deaths of both men in 1961.

Their friendship grew into something of a road show in their later years, as they teamed up for speaking engagements all over the world on the subject of Kaufman and Hart.

“Just two girls with six names,” Ms. Kaufman Schneider liked to say.

“I am very grateful to Anne,” Ms. Carlisle Hart once told The Times. “Anne has taken on the major burden of the plays, their second life.”

In 2004, due in no small measure to his daughter’s restorative efforts, George S. Kaufman formally entered the theatrical pantheon with the Library of America’s publication of “Kaufman & Co.,” a collection of nine of his collaborative comic masterworks.

Still, “for Anne, in the end, nothing made her happier than seeing her father’s plays in front of audiences,” said her executor, Mr. Maslon, an N.Y.U. arts professor and theater scholar who edited “Kaufman & Co.” and who, with the actor David Pittu, is an executor of the George S. Kaufman Literary Trust. “‘Get ’em up!’ was Anne’s watch cry.”

Preserving her father’s plays also allowed Ms. Kaufman Schneider to preserve the love that they each had sometimes found hard to express.

“Well, sir, here we are again,” she wrote on Kaufman’s 51st birthday, when she was nearly 16. “Every year at this time I want to write you a really nice letter and every year I’m just as much at a loss as I was the year before. In between times I can make up gobs of them — I remember things we do together; funny things you say; but those aren’t reasons for writing people birthday letters — those are just a few reasons for liking you. Others are hard to say — hard even to define in thinking terms to oneself.”