Deferment, moratorium periods, and interest capitalization explained

Most guides about student loans focus on repayment and skip over what happens before repayment starts. That gap matters — for many borrowers, a decision made (or made for them) during school quietly determines a meaningful share of what the loan ends up costing.

What a deferment or moratorium period actually is

A deferment (the term used in the US and elsewhere) or moratorium period (common in India and parts of Europe) is a stretch of time — typically while you’re enrolled, plus a short grace period after — during which no payment is due. It’s a genuine benefit: nobody expects a full-time student to be making loan payments out of a part-time income.

What it doesn’t automatically mean is that the loan stops accruing interest. That depends entirely on the loan type.

Two different things happen to that accrued interest

• Subsidized-style: the interest that accrues during deferment is paid by someone else (a government program, typically) or simply not charged. When repayment starts, you owe exactly what you originally borrowed — no more.
• Unsubsidized-style: interest accrues normally throughout deferment, and when repayment begins, that accrued interest is added to your principal — this is called capitalization. From that point forward, you’re paying interest on interest, because the capitalized amount is now part of the balance your monthly payment is calculated from.

The Standard Loan Calculator’s deferment section models exactly this choice — set the deferment length in months, and check or uncheck whether that period’s interest gets capitalized.

Why this matters more than people expect

Consider a 4-year deferment (a typical undergraduate term) on a loan with a non-trivial interest rate. Interest quietly accruing, uncapitalized, for four years can add up to a meaningful fraction of the original principal by the time it’s rolled in — and because it’s now baked into the balance, every future month’s interest is calculated on that larger number for the entire remaining term. It’s the same compounding mechanic that makes extra payments so effective (see the extra payments guide) — just working in the opposite direction.

What you can actually do about it

• Check whether your specific loan is subsidized or unsubsidized (or the local equivalent) before assuming either way — this is one detail worth confirming directly with your lender, since it isn’t always obvious from a loan’s marketing materials.
• If interest is accruing and capitalizing, consider paying it during school if you can, even in small amounts — every dollar paid before capitalization is a dollar that never gets compounded into the balance.
• Run the numbers with and without capitalization on the Standard Loan Calculator to see the actual size of the effect for your loan amount, rate, and deferment length — it’s often larger than people assume, and smaller than people fear, and either way it’s better to know the number than guess.