It means we wouldn't be eligible for FAFSA if I am understanding
@Unconditionalloves correctly. If we have to get private loans then the rate might generally be higher and we wouldn't be able to have them forgiven through federal programs like Public Service Loan Forgiveness (PSLF).
Borrowing through a private lender is usually not ideal for graduate students unless they've exhausted their borrowing cap through the federal government and need more money to cover additional expenses.
(If you come from a rich mommy or daddy home, this wouldn't be an issue because you could pay out of pocket and not need to borrow money for tuition expenses)