Federal Loans - The following loans are all federal loans, and require a FAFSA to determine your financial status.
Stafford Loans: Federal Stafford Loans can help finance a summer study abroad program. These loans have a cap on the maximum loan available by age. So the cap for a junior is $5,500, so this loan is available to be used for summer programs if you are enrolled in a university for the fall semester.
There are drawbacks of using Stafford Loans for a summer study abroad program. One is that using a Stafford Loan for a summer abroad will decrease your aid for college. Another is that this Stafford money is not available until after your summer program. The money becomes available on the first day classes start at your university. So you will need someone to loan you the money first.
PLUS Parent Loans: Parent Plus Loans are loans based on your parents credit score. This is not a need based loan, like the Stafford. They allow your parents to take out a loan covering all of your college expenses. So this loan could be in turn used to pay for a summer study abroad program.
The rate is based on the 91-day Treasury Bill rate for the final May auction of each calendar year. Now, it is at around 6%. The payment for the PLUS loan starts sixty days after it is issued.
Another benefit of this loan is that the interest is able to be tax deducted. The FAFSA is not actually required, but it is very strongly recommended since this is a federal loan.