Any drug offense, even misdemeanor possession charges, can disqualify you from federal loans for a certain period of time. You must either have the charges removed from your record, wait a certain period of time before applying for aid, and/or enter a drug rehab program. Other felonies or misdemeanors do not disqualify you from receiving aid. Defaulting on federal loans, active incarceration, and not complying with selective service registration are other things that might disqualify you from federal student aid.
The drug conviction issue on the FAFSA is a little more complicated than that. If you actually complete the questionnaire that mpp has linked above, you'll find that if you have _any_ drug offences within the last year, you're hosed. But if you have only ONE conviction for POSSESSION (as opposed to selling) and it's been more than one year, you're okay.
I don't know anyone with a drug arrest record who's applied/applying to med school, so I'm not sure about all the other possible roadblocks that may arise if you have a record. Safe to say if you want federal loans, avoiding drugs (or avoiding getting _arrested_ for drugs) is a very good idea.
I finished doing my fafsa, it said my family(me and my spouse) can contribute around 40K 😱😱 . How is it going to affect my financial aid package? Honestly, there is no way my family can afford that kinda money.