Not in medicine, but since no one else is answering, and I do know a bit about paying for grad school....
My question is, what types of sources of funding are available to cover the cost of medical school?
There is a good discussion of this here. In brief, you pay with:
- Your own money (that you already have)
- Scholarships and grants (which don't need paid back)
- Loans
There are also service programs (e.g., in the military), in which they subsidize your education in exchange for a commitment to take a particular job for a few years after you're a doctor.
From what I'm reading, it seems like you can no longer get federal student aid after you have already attained a degree.
This is incorrect; federal student aid and federally-guaranteed student loans are available for both graduate and undergraduate students. The Stafford, Perkins, and Grad PLUS are specifically designed for this situation, and can cover up to the full cost of attendance.
In practice, my (anecdotal) understanding is that loans are the most common source of funding, and most doctors graduate with six figures of debt.
Note, the situation may be different for international students, who would not be eligible for federal student aid, including federally guaranteed loans.