Tuition continues to soar, but there might be some relief for borrowers grappling with student-loan debt: federal income-based repayment programs. Many borrowers may not be aware of them.

Originally designed for those who pursue public-service jobs, the programs have expanded to benefit just about anyone struggling with student-loan debt, especially those with high debt loads and low incomes.

The programs do come with fine print. One major caveat: Only government-backed loans qualify. Loans issued by private companies—which lack many consumer protections—don't.

The current program, rolled out in July 2009, caps the amount of a borrower's discretionary income that goes to repaying a federal loan at 15%. Then, after 25 years, any remaining balance—both principal and interest—is forgiven. If the borrower works in public service, the balance is forgiven after 10 years.

Congress recently passed legislation that expands the program. For federal loans issued after 2014, the cap will be lowered to 10% of income, and the debt is forgiven after 20 years.

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