You may qualify for a better rate if you apply with a cosigner because a co-signer usually has a more established credit history than a student borrower. When applying with a co-signer, both you and the cosigner will complete the application for credit, will sign the loan note and are responsible for repayment of the loan obligation. Keep in mind a private student loan may have a higher interest rate than federal loans, so explore all federal options before applying for a private student loan, only borrowing what you absolutely need.