Paying Interest on Student Loans While Still in School
By Muntasir • Published Aug 02, 2026 • Updated Aug 08, 2026 • US Student Loans
Unsubsidized federal loans accrue interest from the day they disburse, even while you are still in school. Paying that interest as it accrues, instead of letting it sit, keeps it from being added to your principal balance later.
💵 Subsidized loans do not accrue interest while you are in school at least half time
💵 Unsubsidized and PLUS loans accrue interest starting at disbursement
⏱️ Unpaid interest can be added to your principal (capitalized) when it hits certain trigger events
📩 You can pay interest anytime, even $25 a month, with no prepayment penalty
💵 Interest you pay may qualify for a federal tax deduction up to $2,500
Subsidized versus unsubsidized loans
Direct Subsidized Loans do not accrue interest while you are enrolled at least half time, during your grace period, or during an approved deferment, because the federal government covers the interest during those periods. Direct Unsubsidized Loans and PLUS loans start accruing interest the day the loan disburses, regardless of your enrollment status, and you are responsible for all of it.
This means a first-year student who takes out an unsubsidized loan in August starts owing interest immediately, four years before the first payment is typically due.
What happens if you do not pay it
If you do not pay the interest on an unsubsidized loan while in school, it does not disappear. It accrues daily and sits as unpaid interest until a capitalization event occurs, most commonly when an unsubsidized loan exits a deferment period. At that point, the unpaid interest gets added to your principal balance, and from then on you pay interest on that larger amount, including interest on what was previously just interest.
Check studentaid.gov for your loan's exact interest rate and current accrued interest balance, since rates vary by loan type and disbursement year.
How much this costs over four years
The math depends on your loan balance and rate, but the pattern is consistent: the longer unpaid interest sits, the more it costs once it capitalizes. A larger unsubsidized balance carried across four years of school accrues thousands of dollars in interest before you make a single required payment, and all of that can capitalize into principal at once if you never pay any of it during school.
Why paying interest early helps
Paying interest as it accrues, even in small amounts, keeps your principal balance from growing before you graduate. Every dollar of interest you pay during school is a dollar that never gets capitalized, and it never generates interest of its own later. There is no prepayment penalty on federal student loans, so any payment you make while in school goes toward reducing what you owe.
You do not need to make full payments. Many servicers accept interest-only payments while you are enrolled, and even irregular payments of $25 or $50 whenever you have spare cash reduce what capitalizes at repayment.
Comparing your two options
| Approach | What happens to interest | Balance at repayment start |
|---|---|---|
| Pay interest as it accrues | Interest is paid off each period, none builds up | Equals your original principal |
| Pay nothing during school | Interest accrues and sits unpaid | Original principal plus all accrued interest, once capitalized |
The second column matters because a larger starting balance at repayment means a higher required monthly payment on the standard 10-year plan, or more total interest paid if you are on an income-driven plan that stretches repayment over a longer term.
Grace period interest still counts
Your six-month grace period after leaving school on most federal loans is not interest-free for unsubsidized and PLUS loans. Interest keeps accruing through the grace period the same way it did while you were enrolled. If you have the ability to make payments during your grace period, continuing to pay down interest through those six months keeps even more interest from capitalizing when your first required payment comes due.
The tax angle
Interest you pay on qualified student loans, including while still in school, may qualify for the federal student loan interest deduction. You can deduct the lesser of $2,500 or the interest you actually paid during the tax year, according to IRS Publication 970 . For 2025, the deduction phases out for single filers with modified adjusted gross income between $85,000 and $100,000, and for joint filers between $170,000 and $200,000. Most students and recent graduates fall well under these limits, so tracking and claiming interest paid during school can reduce your tax bill even before you start required payments.
How to start paying interest during school
Log into your servicer's website and confirm interest-only or partial payments are accepted while in school
Set up a recurring transfer for whatever amount fits your budget, even a small one
Check your accrued interest balance each semester so you know what you are working against
Keep records of what you paid for tax filing purposes
Common questions
Does paying interest during school lower my minimum payment later?
Yes, indirectly. Your minimum payment on the standard plan is calculated from your balance at the start of repayment. A smaller balance because you paid down interest during school means a smaller required minimum payment, or less total interest paid over the life of the loan if your payment stays the same.
What if I can only afford a small amount?
Paying anything reduces what eventually capitalizes. Even irregular payments during school add up over four years and reduce the balance that starts accruing compound-like growth once you enter repayment.
Do subsidized loans need this strategy too?
No. Subsidized loans do not accrue interest while you are enrolled at least half time or during your grace period, so there is no accrued interest to pay down during school for that portion of your debt.