Instead, "AHS" and "The Sinner" will compete against regular dramas like "Game of Thrones." "American Vandal" will be going up against its fellow comedies, including "Veep" and "The Marvelous Mrs. Maisel."
The decision was made because the most recent seasons of all three shows have "continuing story threads, characters and actors reprising those same character roles from previous seasons," according to the TV academy.
The change might be attributable to the hubbub over "Big Little Lie"s sweeping the "Limited Series" category -- and then announcing a second season that picks up where the first left off.
"American Horror Story" had competed as a limited series every season so far. Although it's an anthology series with standalone seasons, there are recurring characters and plot lines.
Season 2 of "The Sinner," while dealing with a different case than the first season, brought back Bill Pullman as troubled Detective Harry Ambrose.
The academy noted that the changes are for this year's ceremony only. But with Pullman expected to return for Season 3 of "The Sinner," it may be subject to the same rule again.
All three shows were nominated in limited series categories in 2018.
This year's nominations will be announced on July 16. The awards ceremony will be held Sunday, September 22.
[Via Gold Derby]