How old do you have to be to get fat transfer to the butt ?

Hello dear!
Thanks for the question and provided information as well.
You should be at least 18 years old to be a candidate for plastic surgery.
In general, you need to be physically healthy and at a stable weight, have realistic expectations, be a non-smoker and your BMI needs to be 30 or less.
l recommend you to make an appointment with a board certified plastic surgeon to talk about your goals and anything you need to know.
Good luck :)

There is not specific age minimum, but I think most surgeons would wait until you are at least 18 and could consent to the procedure.