Are your loans serviced by Direct Loan Serving (ACS) and are you enrolled in IBR?
You may have received a notice stating that you are in Income-Contingent Repayment (ICR) and your accrued interest will be capitalized if not paid.
Please note that the notice only applies to borrowers who are actually enrolled in ICR. If you are enrolled in IBR your unpaid interest will not be capitalized and no payment is required unless you leave IBR! You may contact ACS for clarification.