It’s another blow to late-night television.

CBS said on Wednesday that it was canceling “After Midnight,” the network’s 12:30 a.m. comedy show, after the host, Taylor Tomlinson, decided to return full time to stand-up comedy.

The late-night comedy genre confronts significant financial challenges as the entertainment world transitions away from traditional television to streaming. The number of late-night shows is dwindling, and many of the survivors are facing pressure to cut their budgets. Audiences and advertising revenue for late-night TV are getting smaller by the year.

Further, the genre, which depends on a large number of episodes and topical humor, has not worked in streaming. Outlets like Netflix and Hulu have introduced original talk shows with a late-night-like format only to cancel nearly every one.

Without “After Midnight,” the 2025-26 season will be the first in three decades that CBS will not have original programming in the 12:30 slot.

CBS executives had renewed the show last week for a third season, which runs from September to May, but canceled it after Ms. Tomlinson’s surprise decision. Its finale will be in June.

Ms. Tomlinson, 31, said in a statement that she wanted to tour as a stand-up — her “first passion” — full time.

Stephen Colbert, the host of CBS’s “The Late Show” and an executive producer of Ms. Tomlinson’s show, which follows his, said in a statement: “While we were excited and grateful for our third season to start in the fall, we respect Taylor’s decision to return to stand-up full time.”

“After Midnight,” which debuted in January 2024, was an experiment. After James Corden stepped aside from “The Late Late Show” in 2023, CBS decided to scrap the traditional late-night format featuring a host, a monologue and a band and try a comedic game show, with a smaller budget and staff.

The move to cancel “After Midnight” — and to remove original programming altogether at 12:30 for the coming TV season — increases the likelihood that CBS will not look for another late-night format in the future.

In recent years, late-night hosts no longer seem interested in having lifetime appointments to the position. Trevor Noah voluntarily left “The Daily Show” in 2022 and then Mr. Corden left “The Late Late Show,” with both hosts saying they wanted to pursue other career opportunities.

Conan O’Brien, the former NBC and TBS late-night host, has found a career renaissance via podcasts, which helped earn him hosting duties for the Academy Awards this month.

CBS has been running original late-night programming since 1993, when David Letterman moved from NBC. “The Late Late Show” debuted at 12:30 a.m. in 1995. Before that, the network had been showing repeats of “bad dramas” in late-night hours, as the network’s former chief executive once put it.