They are Chimamanda Ngozi Adichie, 32; Chris Adrian, 39; Daniel Alarcón, 33; David Bezmozgis, 37; Sarah Shun-lien Bynum, 38; Joshua Ferris, 35; Jonathan Safran Foer, 33; Nell Freudenberger, 35; Rivka Galchen, 34; Nicole Krauss, 35; Yiyun Li, 37; Dinaw Mengestu, 31; Philipp Meyer, 36; C. E. Morgan, 33; Téa Obreht, 24; Z Z Packer, 37; Karen Russell, 28; Salvatore Scibona, 35; Gary Shteyngart, 37; and Wells Tower, 37.

It has been more than a decade since the magazine has published a "20 Under 40" list. The last one, in 1999, included some future literary stars who were then relatively unknown, like Jhumpa Lahiri, Nathan Englander and Junot Díaz. (Relatively established authors like Michael Chabon, Jeffrey Eugenides, and David Foster Wallace were also on the earlier list.)

The new list has its own distinctions. A significant number of the writers hail from outside the United States or have parents who do. All but two (Ms. Obreht and Ms. Russell) are in their 30s. And there is an even number of men and women, a characteristic that Deborah Treisman, the magazine's fiction editor, called "a rewarding accident, in terms of what it says about equal opportunity on the literary playing field these days." (The 1999 list included only five women, The New York Observer noted in May.)

Beyond their age, the writers on the list have nothing in common, said David Remnick, the editor of The New Yorker.

"If they had too much in common, it would be really boring," he said in an interview. "This is not an aesthetic grouping. The group is a group of promise, enormous promise. There are people in there that are very conventional in their narrative approach, and there are people who have a big emphasis on voice. There are people who are in some way bringing you the news from another culture."

It is no secret that publishing these kinds of lists can be tricky. Whatever the intention, they sometimes resemble a publicity stunt. The age cutoff, whether 25 or 35 or 40, can feel capricious. After a list is made public, there is the inevitable sniping that some writers on it were too famous to have been included and that others were unfairly excluded.

"For those people who feel they already know Writer X or Y or 1 through 20, so be it," Mr. Remnick said, naming Mr. Foer as one writer on the new list "who would be, to many, predictable."
Bill Buford, a former fiction editor at The New Yorker who led the compilation of the list in 1999, said he had no regrets about who was chosen for it.

"By gathering up these writers and gathering them up with some authority and some panache, and saying, with all the stuff that's out there, you're saying, here are 20 you should pay attention to," Mr. Buford said, "it's a way of getting those authors to a bigger audience."

The process began in January, when editors in the fiction department started brainstorming. By e-mail they asked literary agents, publishers and other writers to suggest potential candidates.
The editors eventually whittled the possibilities down to a shortlist of roughly 40 eligible writers. A few prominent fiction writers, including Colson Whitehead and Dave Eggers, were slightly too old to make the cut, Ms. Treisman said.

"It's a little agonizing," said Willing Davidson, associate fiction editor at The New Yorker. "We're trying to think of what has this person already done, but also, what are they doing right now that we can put in the magazine?"

Each person who made the shortlist was asked to produce a piece of writing that could be published, whether a short story or an excerpt from a novel. Some had nothing to submit and were taken out of the running.

"The whole thing was so cloaked in weird secrecy," said Ms. Russell, one of the eight writers on The New Yorker's list who also landed on Granta's "Best of Young American Novelists" list in 2007. "It's such a wonderful compliment. But there's a pressure too. You want to honor that vote of confidence. You're like: 'Thanks for putting me in the game, coach. Oh God, I hope I'm not going to be one who is distracted by a butterfly and drops the ball.' "

Behind the scenes the process predictably aroused some competitive jealousies and angling. "Basically everybody I know whose work I like has been scrambling for a spot on this," said Mr. Englander, who appeared on the 1999 list. "If you get on it, then it's a nice confirmation. If you don't get on it, then it doesn't mean anything."

Mr. Ferris, a novelist who made the current list, submitted a short story in April that he began writing in February. "I knew if I made the list, I'd be very happy," he said. "It was the anxiety that it's so utterly out of my hands in the same way that a review might be."
Eight of the writers' pieces of fiction will run in the fiction issue next week; the remaining 12 will run in subsequent issues of the magazine over the course of the summer.

Mr. Díaz, one of the writers on the 1999 list, said that he felt it was a "deep honor," but that he wasn't sure it had an immediate impact on his career.
"I had written a book of short stories about Dominicans," Mr. Díaz said. "I can promise you that there was no bump in sales after the list came out."