Student loans start accruing interest at different moments depending on what you borrowed. Direct Subsidized Loans are the only common type where interest does not build up while you are in school, in your grace period, or in most deferments — the federal government pays it for you. Every other federal loan, including Direct Unsubsidized Loans, Parent PLUS, and Grad PLUS, starts accruing interest the day the funds are disbursed to your school. Private student loans generally follow the same day-one accrual pattern, though the exact terms sit in the lender’s contract.
Direct Subsidized Loans: The One Exception
Direct Subsidized Loans are the only widely available student loan where you get a real pause on interest. The federal government pays the interest during three windows: while you are enrolled at least half-time, during your six-month grace period after you graduate or drop below half-time, and during qualifying deferment periods.1Federal Student Aid. Student Loan Deferment Throughout those periods, your balance holds steady.
Interest on a subsidized loan begins accruing only after your grace period ends and you enter repayment, or during a period of forbearance, which does not carry an interest subsidy. From that point forward, interest is charged daily on your outstanding principal.
If you go back to school at least half-time before your grace period runs out, the subsidy generally restarts, and a fresh six-month grace period is available when you leave school again.
Direct Unsubsidized and PLUS Loans: Interest Starts at Disbursement
Direct Unsubsidized Loans and PLUS Loans work on a completely different clock. Interest starts accumulating the day the funds are disbursed to your school — not when you graduate, not when your grace period ends, but the very first day the money leaves the Department of Education.2Consumer Financial Protection Bureau. Tips for Student Loan Borrowers You are on the hook for every day of interest that builds up from that point, including all the time you are still in school.
This applies to undergraduate unsubsidized loans, graduate unsubsidized loans, and both Parent PLUS and Grad PLUS. Federal law ties each loan type’s rate to the 10-year Treasury note auction, plus a fixed margin: 2.05 percentage points for undergraduate loans, 3.6 for graduate unsubsidized, and 4.6 for PLUS, with statutory caps of 8.25%, 9.5%, and 10.5% respectively.3Office of the Law Revision Counsel. 20 U.S. Code 1087e – Terms and Conditions of Loans The rate is fixed for the life of each loan and set once a year in June for loans disbursed the following academic year.
Parent PLUS borrowers have an extra wrinkle. While the student you borrowed for is enrolled at least half-time, you can request an in-school deferment that postpones payments. Interest still accrues during that deferment, and any unpaid amount gets added to your principal when the deferment ends.4Federal Student Aid. In-School Deferment
Private Student Loans
Private student loans are governed by the contract between you and your lender, not by federal law. In most cases, interest begins to accrue the day the lender sends the funds to your school, just like unsubsidized federal loans. Private lenders generally do not pay any interest on your behalf while you are enrolled.
Some private lenders offer in-school deferment or interest-only payment periods during school, but interest still accumulates daily from disbursement in either case. Any interest you don’t pay during school is typically added to your principal when full repayment begins.
Private loans also frequently carry variable interest rates. Variable rates are tied to a market index such as the Secured Overnight Financing Rate (SOFR) or the Prime Rate, and can adjust monthly, quarterly, or annually depending on your agreement. Your daily interest charge can change throughout the life of the loan as market rates move.
Before your loan is finalized, the lender must give you a disclosure that includes your interest rate, the compounding method, and when interest charges begin.5National Credit Union Administration. Truth in Lending Act Checklist Read it carefully. Private loan terms vary widely, and the details in your specific contract control your obligations.
How Daily Interest Adds Up
Federal student loans use simple interest, calculated only on your current principal balance rather than on any previously accrued interest that has not yet been added to the principal. The formula is straightforward: multiply your principal balance by your annual interest rate, then divide by the number of days in a year.2Consumer Financial Protection Bureau. Tips for Student Loan Borrowers Most servicers divide by 365; some use 365.25 to account for leap years.6Edfinancial Services. Payments, Interest, and Fees
A practical example. If you have a $20,500 unsubsidized loan at 6.39%, the daily interest works out to about $3.59. Over a four-year degree, that is roughly $5,242 in interest that builds up before you even start making payments. For a $5,500 subsidized loan at the same rate, the daily interest would be about $0.96, but the government covers that cost until your grace period ends.
The daily accumulation is why timing matters so much. Each day interest sits unpaid on an unsubsidized or PLUS loan, it adds to the total you will eventually owe. And if that unpaid interest later gets folded into your principal, you start paying interest on interest.
Grace Periods, Deferment, and Forbearance
After you graduate, leave school, or drop below half-time enrollment, most federal loans enter a six-month grace period before repayment begins.7Federal Student Aid. How Long Is My Grace Period? What happens to interest during those months depends on the loan:
- Subsidized loans: the government keeps paying interest through the entire grace period, and your balance does not grow.
- Unsubsidized loans: interest accrues every day of the grace period, even though no payments are due. Unpaid interest may be added to your principal when the grace period ends.
- PLUS loans: interest accrues throughout the grace period, the same way it does on unsubsidized loans.
Deferment is a temporary pause on payments granted for specific reasons — returning to school, economic hardship, unemployment, cancer treatment, or military service, among others. During deferment, the government continues to cover interest on Direct Subsidized Loans and the subsidized portion of consolidation loans.1Federal Student Aid. Student Loan Deferment On unsubsidized and PLUS loans, interest keeps accruing during deferment and you are responsible for it.
Forbearance is a different category. It offers no interest subsidy for any loan type. Interest accrues on subsidized and unsubsidized loans alike.2Consumer Financial Protection Bureau. Tips for Student Loan Borrowers That makes forbearance the most expensive way to pause payments.
When Unpaid Interest Gets Added to Your Balance
Capitalization is what happens when accumulated unpaid interest is added to your principal, creating a larger base on which future interest is charged.8Federal Student Aid. What Is Interest Capitalization on a Student Loan? It is effectively interest on interest, and it can meaningfully increase what you pay over the life of the loan.
Under current Department of Education rules, capitalization on federally held loans happens at specific triggering events:9Federal Student Aid. Interest Capitalization
- End of deferment on an unsubsidized loan: any unpaid interest that built up during the pause is added to the principal.
- Certain changes on the Income-Based Repayment (IBR) plan: voluntarily switching to a different plan, missing your annual income recertification deadline, or no longer qualifying for a reduced payment after recertification all cause unpaid interest to capitalize.
- Consolidation: when you consolidate federal loans, outstanding unpaid interest on the underlying loans becomes part of the new principal.
You can head off capitalization by paying accrued interest before a triggering event occurs. Even small payments directed at interest keep your principal from growing.9Federal Student Aid. Interest Capitalization
Keeping Early Accrual From Snowballing
The single most effective move for unsubsidized and PLUS borrowers is paying interest while still in school. No payments are required during enrollment, but covering the daily interest as it accrues keeps your balance from growing past what you originally borrowed. If full interest payments are not realistic, even small monthly amounts reduce what can later capitalize.
A few other habits that limit early-accrual costs:
- Pay during the grace period. For unsubsidized loans, the six months after you leave school are a chance to knock down accrued interest before it gets rolled into principal at the start of repayment.
- Choose deferment over forbearance when you have the option. If you hold subsidized loans and qualify for deferment, the government picks up the interest. Forbearance never carries an interest subsidy.
- Recertify income-driven plans on time. Missing your annual IBR recertification deadline triggers capitalization of any unpaid interest.
- Think through consolidation before you file. Consolidation turns all outstanding unpaid interest into principal. Paying that interest down first, if you can, keeps it out of your new balance.
Your servicer’s website shows your current principal, accrued interest, and daily interest rate. Those three numbers are what you need to size up how quickly your loans are growing and to decide where to send extra payments if you have them.