I consolidated with Sallie Mae. If you consolidate, make sure you consolidate while in economic hardship or in your grace period. By doing so, you lock in an interest rate that's .5% lower. If you consolidate during forbearance or repayment, you'll lock in on a higher interest rate -- permanently. I locked in at 2.875% with a .25% reduction for direct payments and a 1% reduction with 36 consecutive ontime payments. So after 3 years, my interest rate will be 1.625%. Not bad, not bad at all!
Regarding the 1993 thing...
The government eliminated the automatic deferment in residency. However, you are not required to make payments during residency or graduate fellowships. Here's what you get:
Grace period -- 6 months after you graduate. Subsidized loans are paid and your interest rate is the lower (currently 1.6% I believe).
Economic hardship -- up to 3 years. To qualify, your monthly payments must be greater than 20% of your gross monthly salary (based on a 10-year payment schedule, regardless if your actual consolidation is set up on a 30-year schedule). Your income also cannot exceed 220% of the federal poverty level for a family of two. Economic hardship means you get the lower interest rate and your subsidized loans have interest paid by the government (just like the grace period).
Forbearance -- if you don't qualify for economic hardship and cannot make payments, then this is your option to avoid payments during residency. Your interest rate is higher (2.4% I believe), but you can get around this if you consolidate during your grace period or economic hardship period. Miss the boat and consolidate during forbearance and you lock into the higher interest rate -- permanently. Subsidized loans accrue interest during forbearance. Use this option only if you cannot qualify for economic hardship. I believe you can use this for up to 5 years, but don't quote me on that.
If you use the economic hardship for 2 years, then consolidate, most companies will allow you to "refresh" or "renew" your hardship status for another 36 months. Some companies will not, so make sure the company you are consolidating with will allow you to do this if you are in a 5-year residency program, such as surgery.