Under the REPAYE plan, your monthly payment is generally 10% of your discretionary income. Discretionary income is defined as the difference between your adjusted gross income and 150% of the poverty guideline for your family size and state of residence. If your income increases over time, so will your monthly payments. The plan also offers loan forgiveness after 20 or 25 years of qualifying payments, depending on whether the loans were taken out for undergraduate or graduate studies.