Capitalized Interest: How Your Student Loan Balance Grows While You Pause Payments

If you have federal student loans, you have probably heard about deferment and forbearance. These options let you temporarily stop making payments when you are in school, unemployed, or facing a financial hardship. They sound like a lifeline. But there is a hidden cost that can turn a manageable loan into a nightmare: capitalized interest.

Capitalized interest is the process where unpaid interest gets added to your loan principal. When that happens, you start paying interest on the interest. It is like a snowball rolling downhill, picking up more snow as it goes. For middle-class borrowers who already have tight budgets, this can be the difference between a debt you can handle and a debt that spirals out of control.

Think of interest as the cost of borrowing money. Every day your loan is outstanding, interest accrues. When you make a regular payment, that payment covers the interest that has accumulated since your last payment, then reduces the principal. But during deferment or forbearance, you are not required to make payments. That does not mean interest stops growing. It keeps adding up. With subsidized federal loans, the government pays the interest during certain deferments, but for unsubsidized loans and PLUS loans, you are responsible for every penny of interest that piles up.

The real problem starts when the deferment or forbearance ends. Your loan servicer looks at the total unpaid interest that built up during those months. That amount is then added to the original amount you borrowed. This new, larger balance is your new principal. From that point forward, your monthly payment is recalculated based on the higher number, and interest charges are computed on that inflated principal.

Here is a concrete example. Suppose you graduated with $30,000 in unsubsidized loans at a 6% interest rate. After graduation, you have a six-month grace period, during which interest accrues. Then you hit a rough patch and request a 12-month forbearance. During that year, the interest on your $30,000 loan is roughly $1,800. That $1,800 gets capitalized when the forbearance ends. Now your new principal is $31,800. From then on, you are paying interest on $31,800 instead of $30,000. Over the life of a 10-year repayment plan, that extra $1,800 can cost you hundreds of additional dollars in interest.

The danger is worse if you use multiple forbearances or long deferments. Some borrowers end up in what is called “negative amortization.” This happens when your monthly payment is less than the interest that accrues each month. The unpaid interest gets added to the principal, and the balance actually grows even though you are making payments. Income-driven repayment plans can sometimes cause this if your payment is set very low. That is another way capitalized interest can quietly inflate your debt.

Why does this matter for middle-class consumers? Because many of us are forced to use deferment or forbearance when unexpected expenses hit: a medical bill, a car repair, a temporary layoff. We think we are buying time, but we are actually making the long-term cost worse. A study by the Consumer Financial Protection Bureau found that nearly one in five federal student loan borrowers in forbearance saw their balances increase because of capitalized interest. For those who are already struggling, this can transform a manageable loan into an overwhelming burden.

What can you do to protect yourself? First, avoid forbearance if possible. If you qualify for an income-driven repayment plan, that is almost always a better option. Plans like PAYE or REPAYE base your payment on your income, and any unpaid interest may be partially subsidized by the government. Even a $0 payment on an IDR plan counts toward loan forgiveness after 20 or 25 years, and it prevents interest from capitalizing in the same way. Second, if you must use forbearance, try to pay at least the interest that accrues during that time. Even a small monthly payment can stop the snowball. Third, consolidate your loans only if you understand the trade-offs. Consolidation can reset your payoff timeline and can also cause previously unpaid interest to capitalize.

Finally, know your loan servicer. Call them before you enroll in forbearance and ask exactly how interest will be handled. Some servicers are required to tell you about capitalization, but not all do a good job of explaining it. Write down the date when capitalization will happen and how much interest will be added. This is your money. Treat it that way.

Student loans are already a heavy weight for middle-class families. Capitalized interest makes that weight heavier without most people noticing until it is too late. By understanding how it works, you can make smarter choices about when to pause payments and when to push through the hardship. The goal is not to avoid every bump in the road; it is to keep your debt from growing when you are not looking. A little knowledge now can save you thousands of dollars and years of repayment agony.