If you don’t make your loan payments, and your loan is delinquent, you risk going into default. If you are in default, you will lose eligibility for additional federal student aid. You will need to get out of default before you can receive aid again. (Note: You can still submit the FAFSA if you're in default, you just won't be eligible for additional aid).
If you’ve defaulted on any of your federal student loans, contact the organization that notified you of the default as soon as possible so you can explain your situation fully and discuss your options. If you make repayment arrangements soon enough after your loan has gone into default, you may be able to resolve the default quickly. Find out who holds your loan by logging in to “My Federal Student Aid.”
One way to get out of default is to repay the defaulted loan in full, but that's not a practical option for most borrowers. The two main ways to get out of default are loan rehabilitation and loan consolidation. While loan rehabilitation takes several months to complete, you can quickly apply for loan consolidation.
However, loan rehabilitation provides certain benefits that are not available through loan consolidation. You can find more information here, including a chart that compares the benefits of loan rehabilitation versus the benefits of loan consolidation.