I actually have been meaning to call them to clarify. My understanding is that you are supposed to be making monthly or quarterly payments while you are in school (as skaballet said). That is the whole point of unsubsidized - you still pay the interest. For subsidized, while you are in school, the government pays the interest on your behalf. However, I have never received a bill and when I log in to look at my balance, my interest is accruing, yet the principal is unchanged, so I can't really figure it out. I decided to just pay it monthly and not worry about it.
"Egotism is the anesthetic that dulls the pain of stupidity." - Frank Leahy
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