I'm not a medical student, but the financial part works out the same way as in undergrad, so loans are available for housing. I do know that working while in medical school is discouraged due to the time needed for everything.
Not taking into account scholarships and grants, students will borrow
at least the cost of tuition. Then, they will borrow
up to the total cost of attendance. The total cost of attendance includes the cost of tuition + housing, food, transportation, etc. The amount you borrow beyond cost of tuition is highly variable. It can depend if you have roommates, if you have a car, or if you have a rich uncle sending you money.
By looking at the average indebtedness at any medical school most students do not borrow the total cost of attendance every year. Here is a link to how much in loans you can borrow at HUCM if needed.
http://medicine.howard.edu/finance/costs.htm