How to Pay Interest on Student Loans: Avoid Capitalization

To pay interest on student loans, log in to your loan servicer’s website, find the accrued interest figure on your dashboard, choose the option to make a one-time payment, and specify that the money should be applied to accrued interest rather than held as a prepayment on your next bill. That last step is what separates a payment that actually reduces your balance from one that just sits there waiting for the next statement. The whole process takes a few minutes once you know where to click and what to tell the servicer.

Find Your Loan Servicer First

Every payment goes through your servicer, the company that handles billing for the Department of Education. If you don’t know who yours is, log in to your Federal Student Aid account at studentaid.gov with your FSA ID. The dashboard lists every federal loan you hold and names the servicer assigned to each one.¹ Major federal servicers include MOHELA, Nelnet, Aidvantage, and EdFinancial.

Once you have the name, create an account on that servicer’s site if you don’t already have one. You’ll need your loan account number, which appears on any billing statement and inside the portal after you sign in. For private student loans, the lender is the servicer, so check your original loan documents.

Make the Payment and Tell the Servicer Where It Goes

Inside the servicer’s portal, look for a figure labeled “Outstanding Interest” or “Accrued Interest.” That’s the running total of interest that has built up but not yet been billed. To pay it down before it becomes part of your principal, choose the “make a payment” or “one-time payment” option rather than waiting for a scheduled monthly bill.

When the form asks how you want the payment applied, direct it to accrued interest. If there’s a text box for instructions, write something plain like “Apply to accrued interest.” This matters because of what the industry calls paid-ahead status: when you send extra money without instructions, some servicers credit it toward your next monthly bill instead of reducing your balance, which doesn’t help you at all.² You can call your servicer and ask them to turn off paid-ahead status entirely, so every extra dollar you send goes toward your balance from then on.

To finish the payment, enter your bank routing and account numbers, confirm the amount, and save the transaction confirmation. Most servicers email a receipt within minutes, and the payment usually posts in your account history within two to three business days.

Paying by Check

If you’d rather mail a payment, write your loan account number in the memo line. Print the payment coupon from your servicer’s site or your monthly statement and send both to the servicer’s payment processing address, which is often not the same as the general correspondence address.³ Look for a “Where to Send Payments” section on the site to confirm.

Set Up Auto-Pay for a Rate Discount

Federal loan servicers cut your interest rate by 0.25% while you’re actively enrolled in automatic payments.⁴ The discount goes away during deferment or forbearance and can be revoked if three consecutive payments bounce for insufficient funds. It kicks back in automatically once your deferment ends and payments resume.

When Interest Payments Make the Biggest Difference

You don’t have to wait for a bill. Servicers accept voluntary payments any time, and there are stretches when paying interest yourself is the whole point.

While you’re still in school: Interest on unsubsidized loans accrues daily even though no monthly statement arrives. Small payments during this period keep the balance from growing.⁵
During the six-month grace period: Most federal loans give you six months after graduation, leaving school, or dropping below half-time before payments are required. Interest on unsubsidized loans keeps building through this window.¹
During deferment or forbearance: Interest on unsubsidized loans continues to accrue. Subsidized loans are protected during deferment because the government pays that interest, but they are not protected during forbearance.
During active repayment: You can always pay more than your required monthly amount to knock accrued interest down faster.

Direct Subsidized Loans are the exception across most of this list. If you have subsidized loans, the government pays your interest while you’re enrolled at least half-time, during the grace period, and during any deferment.⁶ You don’t need to send interest payments during those stretches because nothing is accruing on your account. Unsubsidized loans, PLUS loans, and grad loans get no such break.

Pay Down Interest Before It Capitalizes

Capitalization is the event that turns your accrued interest into new principal. Once that happens, you start paying interest on the higher balance, which is how student loan debt compounds.⁵ For federal loans held by the Department of Education, capitalization is triggered by specific events:

The end of a deferment on an unsubsidized loan.
Leaving an income-driven repayment plan by switching plans, missing the annual income recertification deadline, or no longer qualifying for a reduced payment after recertifying.⁷
The end of the grace period on an unsubsidized loan, when unpaid interest from school and the grace period is added to principal.
Consolidating federal loans into a Direct Consolidation Loan, which folds all unpaid interest on the underlying loans into the new principal.⁸

The move is to log into your portal a few weeks before any of these events, check your accrued interest, and pay it down. A partial payment still reduces the amount that capitalizes.⁷

How Your Servicer Applies What You Send

Payments aren’t split however you want by default. The standard order is outstanding fees first (late fees, for example), then accrued interest, then principal.² Anything beyond what’s owed goes to principal, unless the servicer puts you in paid-ahead status instead.

If you have multiple loans under one account, the servicer usually splits your payment proportionally across all of them. You can call or send written instructions asking that a payment target a specific loan, which is useful when you want to attack the one with the highest interest rate first. Get the instruction on record. The default allocation isn’t always the one that benefits you most.

Paying Interest on Private Student Loans

Private loans use the same basic daily interest formula but lack federal protections. No private lender offers a subsidized benefit, so interest accrues from the day the money is disbursed. Many private lenders also use variable rates, so your daily interest charge can rise as market rates shift.

Federal law prohibits private lenders from charging prepayment penalties, so you can make interest-only payments or pay off a loan early without a fee.⁹ The process looks a lot like the federal one: log in, make a payment, and specify that it should go to accrued interest or principal rather than sit as a prepayment on future installments.

Claim the Interest You Paid on Your Taxes

The interest you pay each year can trim your federal tax bill. The student loan interest deduction lets you subtract up to $2,500 in interest paid during the year from your taxable income.¹⁰ It’s an above-the-line deduction, meaning you can claim it without itemizing.

Eligibility depends on your modified adjusted gross income. For 2026, the deduction begins phasing out at $85,000 for single filers and disappears entirely at $100,000. For joint filers, the phase-out runs from $175,000 to $205,000.¹⁰ A handful of other requirements apply:

You have to be legally obligated on the loan. If a parent took it out, the parent claims the deduction, not the student.
You can’t be claimed as someone else’s dependent.
You can’t file as married filing separately.
The loan must have paid for qualified education expenses such as tuition, room and board, books, and other costs of attendance at an eligible institution. Refinanced loans still qualify as long as the original debt covered education expenses.¹¹

If you paid more than $600 in interest during the calendar year, your servicer is required to send you IRS Form 1098-E showing the deductible amount.¹² If you paid less, the servicer doesn’t have to send the form, but you can still claim the deduction. Pull the year-end interest statement from the servicer’s portal and keep it with your tax records.

1
Federal Student Aid. Repaying Your Loans
2
Consumer Financial Protection Bureau. How Is My Student Loan Payment Applied to My Account?
3
Nelnet. Understanding Your Monthly Student Loan Statement
4
MOHELA. Auto Pay Interest Rate Reduction
5
Consumer Financial Protection Bureau. How Does Interest Accrue While I Am in School?
6
Federal Student Aid. Top 4 Questions: Direct Subsidized Loans vs. Direct Unsubsidized Loans
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Nelnet. Interest Capitalization
8
Federal Student Aid. 5 Things to Know Before Consolidating Federal Student Loans
9
Office of the Law Revision Counsel. 15 U.S. Code 1650 – Preventing Unfair and Deceptive Private Educational Lending Practices and Eliminating Conflicts of Interest
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Office of the Law Revision Counsel. 26 USC 221 – Interest on Education Loans
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Office of the Law Revision Counsel. 26 U.S. Code 221 – Interest on Education Loans
12
Internal Revenue Service. Instructions for Forms 1098-E and 1098-T