<p>Or do you have until May 1 to reply?</p>
<p>You don’t have to reply until May 1, but it’s considerate to do so, since there are people on the waitlists at the schools you are choosing not to attend. The sooner each school gets an accurate sense of their acceptances/rejections, the sooner they can begin notifying the waitlist people.</p>
<p>Don’t withdraw, though, unless you are absolutely positive where you want to go. You can’t backtrack later.</p>
<p>You don’t need to freak out about having all of your files closed at the exact moment you commit, but it is simply good etiquette to let them know when you have made your decision.</p>