Dear Grace, In the US , you have to get parents consent for any elective surgery , when you are under the age of 18. In the 11 years that I am performing butt augmentation, I have never done it on patients under the age of 18, for the obvious reason that parents do not agree to it. Interestingly, I have done breast augmentations under 18 with parents consent... Another thing that you should consider is the fact that fat injection to the butt do not last beyond 6 - 12 months, so your best option when you turn 18 is butt implants. Finally, always consult with board certified plastic surgeons who do lots of butt implants surgery. Check the before and after pictures to make sure that you like the results, because there are different techniques and different implants shapes. Best of luck, Dr Widder