First of all, I would like to thank all of you who post on these forums. I've been reading it thoroughly ever since my first post here, and have found a wealth of information. It has helped me a lot. Especially ZapperZ's wonderful "So you want to be a physicist" guide. My question is regarding loans. I have read on these forums, to my relief, that around 90% of graduate students in physics get their tuition payed for by some means, plus a stipend. However, what would this mean if I still were to have a substantial amount of debt from my undergrad years? Would I have to begin paying down the debt while I was in graduate school? And if so, would it be possible to do that with the amount of money a graduate student is expected to live on? If you need a specific amount of debt in order to answer, assume it's in the $20,000 to $40,000 range. Thanks in advance for any help that can be provided.