During a deferment, any accrued interest on subsidized loans will be paid by the U.S. Department of Education; however, you remain responsible for any accrued interest on your unsubsidized or PLUS loans. If you do not pay the interest during the deferment period, it will be capitalized (added to your principal balance) at the end of the deferment period. You can use this calculator to see what the cost of a deferment might be.