I don't think you can file the paperwork while you are still in an in-school status. If you are like most students, you will have a grace period after you graduate (interest doesn't accrue on subsidized loans, variable interest rate loans stay at the lower in school rate) that will last long enough for you to actually be in residency and have a paycheck. Once you have the paycheck stub you can file the paperwork without difficulty. It is good that you want to be proactive about this, but you are jumping the gun by quite a bit. The stafford loans have a 6 month grace period, while the perkins have a 9 month grace.
Do be careful though, because they will send you paperwork showing you first payment's due date which is after the end of the grace period. You want to have your paperwork in before that (not too much before so you take full advantage of your grace period) to maximize your interest savings. Just look at a calendar and calculate 6 months from your graduation date (another potential problem-your school may report one date, then change it later and end up causing problems). Apply for the deferment a couple of weeks before that (it took about three days for mine to go through, but your lender may be different and there might be busy times). This should be around November for May graduates.
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Thanks for the info, Since I consolidated my loans, I gave up my grace period. My loans go into repayment 5/27/07 (day after graduation) with my first payment scheduled to be due 6/27/07. So I should probably wait till right after graduation when my "in-school" deferment ends, then I could apply for Economic Hardship right after that to make sure the paperwork is in a few weeks before my first payment is supposed to be due. Does this sound right?
Thanks