What if the decision deadline is before other schools' decision releases?

For Johns Hopkins University, decisions are released May 15. The respond deadline is May 30. Other schools do not release decision until June 1. Do schools usually extend the decision deadline? Would calling and asking JHU hurt my chances since it implies JHU is not my first choice?

There’s a couple ways you can play it.

  1. If you get into JHU, you can submit your nonrefundable deposit (somewhere between 200-500 normally). Then, if you get into somewhere you prefer more, you lose your deposit.

or

  1. If you get accepted you can call and say you just don't have enough time to decide, and see if they will extend your deadline. Whether or not they do that can honestly depend on factors as small as whether the person you talk to is in a good mood lol.