Where your student loan payment goes each month

When you make a student loan payment, the money does not all reduce what you owe. Your payment is split between interest that has accumulated since your last payment and principal — the actual loan balance. The exact split depends on your loan type, how much interest has built up, and which repayment plan you are on.

Federal student loans send payments to your loan servicer, the company that manages your account on behalf of the Department of Education. Your servicer applies the money according to federal rules: interest accrues daily based on your outstanding balance and interest rate, and anything left after interest goes toward principal. Private student loans work similarly but follow the terms in your promissory note, which can vary by lender.

If you are in deferment or forbearance — periods when you are not required to pay — interest may still accrue on unsubsidized loans, meaning you owe more even though you are not making payments. On subsidized federal loans, the government covers interest during these periods, so your balance does not grow.

Key Takeaways

  • Each payment covers accrued interest first, then reduces your principal balance, so early payments in a loan's life go mostly toward interest.
  • Federal loans are serviced by companies like Nelnet, Mohela, or Aidvantage, which explore payments according to Department of Education rules.
  • Your repayment plan — Standard, Income-Driven, or Graduated — determines your monthly payment amount but not how payments are split between interest and principal.
  • Unsubsidized loans accrue interest even during deferment or forbearance, so your balance grows if you are not paying.
  • Making extra payments toward principal can shorten your loan term and reduce total interest paid over the life of the loan.

Federal versus private loan payment routing

Federal student loans are held by the Department of Education but serviced by a contractor. As of 2024, the major servicers are Nelnet, Mohela (Missouri Higher Education Loan Authority), Aidvantage, and Edfinancial. Your servicer collects your payment, records it in your account, and reports it to your credit file. You can find which servicer handles your loans by logging into studentaid.gov or calling 1-800-4-FED-AID.

Private student loans are held by the lender directly — companies like Sallie Mae, Discover, or Wells Fargo. You send payments to the lender's payment portal or by mail, and the lender applies the money to your account. Private lenders have more flexibility in how they structure payments, so the terms in your promissory note control whether you can make extra payments without penalty and how payments are applied.

Both federal and private servicers typically allow you to set up automatic payments, which often come with a small interest rate reduction — usually 0.25 percent. Automatic payments also reduce the risk of missing a due date, which triggers late fees and credit reporting.

How interest and principal are calculated on your payment

Interest on federal student loans accrues daily. Your servicer calculates it by multiplying your outstanding balance by your interest rate, then dividing by 365. If your balance is $25,000 and your rate is 6 percent, you accrue about $4.11 per day in interest. Over 30 days, that is roughly $123 in interest before you make a payment.

When you submit a payment, your servicer applies it in this order: first to any collection costs or late fees, then to accrued interest, then to principal. If you owe $123 in accrued interest and make a $200 payment, $123 goes to interest and $77 reduces your balance. This is why early in a loan's life — when your balance is high — most of your payment covers interest rather than principal.

Private loans follow the same general logic but may have different rules in the fine print. Some private lenders allow you to specify that extra payments go to principal only, while others explore all payments in the standard order. Check your loan documents or contact your lender to confirm.

Repayment plans and how they affect your monthly payment

Standard Repayment sets a fixed payment amount over 10 years. For federal loans, this is the only plan that does not require income documentation. Your payment is calculated so that you pay off the loan in exactly 10 years, assuming you make every payment on time.

Income-Driven Repayment plans — SAVE, PAYE, REPAYE, and IBR — calculate your payment based on your discretionary income and family size. Your payment may be as low as $0 per month if your income is below the poverty line. Interest still accrues, so if your payment does not cover accrued interest, your balance grows even though you are making payments. These plans offer forgiveness after 20 to 25 years of payments, though forgiveness may trigger a tax bill.

Graduated Repayment starts with a lower payment that increases every two years over 10 years. It is designed for borrowers who expect their income to rise. Your total interest paid is usually higher than Standard Repayment because early payments are smaller.

Your repayment plan does not change how payments are split between interest and principal — that is determined by how much interest has accrued. The plan only determines your monthly payment amount.

What happens if your payment does not cover accrued interest

On income-driven plans, it is possible to make a payment that does not cover all the interest that has accrued since your last payment. If you owe $150 in accrued interest but your payment is $100, your servicer applies the $100 to interest, and the unpaid $50 is added to your principal balance. This is called negative amortization, and it means your loan balance grows even though you are paying.

Negative amortization is most common on SAVE and PAYE plans when your income is very low. The Department of Education caps unpaid interest: on SAVE, unpaid interest is forgiven after 20 years; on PAYE and REPAYE, after 25 years. On other plans, unpaid interest accrues indefinitely.

If you want to avoid negative amortization, you can pay more than your required payment. Any amount above your monthly obligation goes directly to principal. Some borrowers on income-driven plans make small extra payments when their income rises to cover the accrued interest and prevent their balance from growing.

Making extra payments and paying off your loan early

Federal student loans have no prepayment penalty, so you can pay as much as you want without extra fees. If you make a payment larger than your monthly obligation, the servicer applies the full amount to your account — the extra goes to principal after interest is covered. You can also request that extra payments be applied to a specific loan if you have multiple federal loans.

Private loans also typically have no prepayment penalty, but check your promissory note to be sure. Some private lenders allow you to designate extra payments as "principal only," which bypasses the interest-first rule and goes straight to reducing your balance. This can save you money if you are making large extra payments.

Paying extra principal shortens your loan term and reduces the total interest you pay over the life of the loan. If you have a $25,000 loan at 6 percent over 10 years, your monthly payment is about $278. If you add $50 per month, you pay off the loan in roughly 8 years and save about $1,500 in interest. The earlier you start making extra payments, the more interest you save.

Late payments, deferment, and how they affect your balance

If you miss a payment, your servicer charges a late fee — usually 6 percent of your monthly payment amount, capped at $15 for federal loans. The late fee is added to your balance. After 90 days of nonpayment, your loan is reported to credit bureaus as delinquent. After 270 days, federal loans go into default, which can trigger wage garnishment and loss of future aid.

If you cannot pay, you can request deferment or forbearance — periods when you are not required to make payments. On subsidized federal loans, the government covers interest during deferment, so your balance does not grow. On unsubsidized loans and all private loans, interest accrues during both deferment and forbearance. If you defer an unsubsidized loan for one year without paying, your balance increases by the amount of accrued interest, even though you made no payments.

Forbearance is easier to obtain than deferment but more costly: interest accrues on all loan types, and the accrued interest is usually capitalized — added to your principal — when forbearance ends. This means you owe more than you did before forbearance began.

Frequently Asked Questions

Can I choose which of my loans get paid first if I have multiple federal student loans?

Yes. When you make a payment larger than your required monthly amount, you can contact your servicer and request that the extra go to a specific loan. This is useful if you have loans at different interest rates and want to pay off the highest-rate loans first. Some servicers allow you to set this preference in your online account.

What is the difference between capitalization and accrual?

Interest accrues when it builds up but is not yet added to your balance. Capitalization is when accrued interest is added to your principal. Once interest is capitalized, you pay interest on the interest. This happens at the end of forbearance periods and when you leave school on an unsubsidized loan.

If I pay my student loan off early, do I save money?

Yes, because you stop accruing interest once the loan is paid in full. The earlier you pay it off, the less total interest you pay. However, if you have federal loans with a low interest rate and other high-interest debt, it may make financial sense to pay the high-interest debt first.

Do I have to make monthly payments, or can I pay more frequently?

You can pay more frequently if you want. Some borrowers make biweekly or weekly payments to reduce the amount of interest that accrues between payments. Your servicer will explore each payment to your account as it arrives, so more frequent payments mean less total interest over the life of the loan.

What happens to my payment if I am on an income-driven plan and my income changes?

Your payment does not change automatically. You must recertify your income each year by submitting a new income form to your servicer. If your income rises, your payment increases. If your income falls, your payment decreases. If you do not recertify, your servicer may place you on Standard Repayment, which is usually a much higher payment.