Public radio has been good for David Sedaris, and vice versa. In 1992, the then-unknown writer started to turn tales about his quirky upbringing and odd-job work history into the stuff of hilarious, and golden, memoir.

Starting with his reading on NPR of a now-beloved story about his experiences as an elf for a Macy’s Santa Claus, Sedaris has grown into one of America’s preeminent humorists, with a string of best-selling story collections. In addition to NPR’ s news programs, he is a semi-regular contributor to “This American Life,” a weekly public-radio program that features extensive first-person, nonfiction stories.

But in the wake of an episode in March in which a contributor to “This American Life” admitted to fabricating facts and people in his story, Sedaris’s work is undergoing new scrutiny.

The immediate question is whether Sedaris’s stories are, strictly speaking, true — an important consideration for journalistic organizations such as NPR and programs such as “This American Life.” A secondary consideration is what, if any, kind of disclosure such programs owe their listeners when broadcasting Sedaris’s brand of humor.

Then there’s this: Does it matter whether a humorous writer, working on a news or nonfiction program, makes stuff up?

Unlike a stand-up comedian or a comic literary stylist such as James Thurber, who engaged in obviously implausible situations, Sedaris’s stories fall into a gray area. They are rooted in real events and populated by presumably real people, with their humor derived from Sedaris’s comic “voice.” These exaggerations and comic interjections are evident to a listener or reader, and Sedaris has attested that they are essentially autobiographical. His best-selling books, such as “Naked” and “Barrel Fever,” have been sold as nonfiction.

Except it’s not that simple.

In a lengthy investigative article for New Republic magazine in 2007, writer Alex Heard fact-checked Sedaris’s output and found that he had invented characters and concocted important scenes in some pieces. In one story, for example, Sedaris described working as an orderly in a mental hospital with a co-worker named Clarence. Although Sedaris had once volunteered in the hospital, he told Heard that he hadn’t been an orderly and that Clarence was imaginary. The magazine titled Heard’s article “This American Lie.”

According to Heard, Sedaris also invented parts of a story called “SantaLand Diaries,” about his Christmastime experiences working at Macy’s. The story has become one of NPR’s most requested features and has been replayed on the daily “Morning Edition” program every year around Christmas since 2004.

In an author’s note in his most recent book, “When You Are Engulfed in Flames,” Sedaris seemed to concede that not every experience he describes happened. He called his tales “realish.” (Sedaris could not be reached for an interview for this article.)

According to host and producer Ira Glass, “This American Life” began discussing Sedaris’s contributions to the program after an embarrassing episode in March, in which it acknowledged that a monologue by writer Mike Daisey contained numerous fabrications. The show “retracted” the program it aired in January, in which Daisey described harsh working conditions in the Chinese factories that make Apple’s iPhone, iPad and other products. Glass told listeners that Daisey had invented scenes, facts and people — which is exactly what Sedaris has said he’s done.

While the stories themselves are hardly equals — Daisey’s was a hard-hitting exposéabout industrial exploitation, Sedaris’s essays are light and personal — they both raise the question of what’s permissible in the context of a nonfiction program.

“Some of his characters are made up. You can’t use a nonfiction label and do that,” said Heard, the editorial director of Outside magazine. “Hilarious dialogue is the license he gave himself. . . . [But] if it’s nonfiction, you just can’t do that.”

Others defend Sedaris and his presentation by NPR and “This American Life,” saying the liberties he takes are justified because his intention is to draw laughs, not report serious information.

“I don’t think David ever posed himself as a journalist,” said Torey Malatia, who heads Chicago Public Media, which produces “This American Life.” “He’s a storyteller, a humorist. The giveaway is when he’s wildly exaggerating. It’s art. It’s fiction.”

Said Ellen McDonnell, NPR’s executive editor of news programming: “I guess, to me, [“SantaLand”] was just a holiday story. I mean, he was an elf! It was not a he said-she said, who-what-why story like Mike Daisey.”

Alicia Shepard, NPR’s former ombudsman and a visiting journalism professor at the University of Nevada at Las Vegas, had a similar view. “David Sedaris has never been presented as a journalist,” she said. “He’s a storyteller. I do think there are different expectations. It’s acknowledged that he’s making things up.”

In fact, listeners would be unlikely to know this by the way NPR and “This American Life” present Sedaris on the air. NPR introduced its last rebroadcast of Sedaris reading “SantaLand” in December by calling it “a ‘Morning Edition’ holiday tradition.” It has used similar language in each of its rebroadcasts.

“This American Life” rebroadcast an old Sedaris monologue on May 5 — a nearly 15-minute piece about his family’s pets — without any hint that parts of it might have been untrue.

In an interview, Glass said no one at his program was concerned about Sedaris before the Daisey episode. “We just assumed the audience was sophisticated enough to tell that this guy is making jokes and that there was a different level of journalistic scrutiny that we and they should apply,” he said.

But the Daisey debacle has brought about a reassessment. Glass said three responses are under discussion: fact-checking each of Sedaris’s stories to ensure their accuracy, labeling them to alert the audience that the stories contain “exaggerations” or doing nothing.

At the moment, Glass said, he thinks the best course is to check Sedaris’s facts to the extent that stories involving memories and long-ago conversations can be checked. The New Yorker magazine subjects Sedaris’s work to its rigorous fact-checking regime before it publishes his stories.

Glass says labeling Sedaris’s stories presents its own problems: “It’s a hard thing to figure out how to do it in way that is respectful of the audience and is respectful of Sedaris.”

But people at NPR, which is separate from “This American Life’s” producer, Chicago Public Media, think the label option makes sense.

“When you have so much questioning of what’s real, fair, subjective and accurate in the news media, it doesn’t help to have [a segment] on a news program that gives no indication that some liberties have been taken,” said Edward Schumacher-Matos, NPR’s ombudsman, its independent in-house critic. “I do think some kind of flag or label or introduction would be appropriate.”

McDonnell and Shepard agree that a reader alert is warranted. Shepard suggests calling Sedaris’s work “a blend of fact and imagination.”

McDonnell goes further: “In my very clear hindsight, you’d call it fiction.”