Does IT have a post-credit scene?

No post-credits scene — but leaving early costs you the film's real last beat. IT puts its sequel tease before the credits: after Beverly's vision and the Losers' blood oath on the Barrens, a card reading "IT: Chapter One" drops in, retroactively renaming the film you have just watched and announcing that a second half exists. Warner Bros. had not formally confirmed Chapter Two at that point. The card did it for them.

Then the credits run, several minutes of them, apparently uneventful. Right at the end of the roll a children's chorus starts singing "Oranges and Lemons" — the nursery rhyme the film has been using as Pennywise's calling card — and underneath it, once the last name has cleared, comes a full, unhurried laugh from the clown. No image, no title, just the laugh, held long enough to make its point: the thing the Losers beat down a well is not dead, it is dormant, and it has twenty-seven years to wait.

There nearly was a filmed scene there. Andy Muschietti has described the version he wanted — a phone ringing twenty-seven years later, a hand reaching for it, the camera arcing around a red-haired woman, and Jessica Chastain revealed as the adult Beverly Marsh before Chapter Two had shot a frame. Producer Barbara Muschietti has said the schedules never lined up and the sequence was abandoned rather than recast with someone else; the compensation was that Chastain did end up playing the part in 2019, exactly as intended.

So the arithmetic is simple. The title card is a sequel tease you get for free before the credits start. The laugh is an audio sting you only get by sitting through all of them, and it is the more effective of the two — a horror film's version of a mid-credits button, delivered without spending a single frame of picture on it. If you are watching at home, turn off autoplay before the credits begin, because most streaming apps will cut away before the chorus arrives.