You can go to The National Student Loan Data System (NSLDS) site , click on the button “Financial Aid Review”, read statement and click “Accept”, answer the required questions (SSN, DOB, first two letters of last name, FAFSA Pin#) and click submit. Here is a list of your loans and the lender/servicer. Click on the Servicer’s name and you will be taken to information about how to contact them.
Once you know your lender/servicer you can go to their website and create an account to help you keep track of payments, interest rates, repayment plans, etc.