She Paid $412 A Month For Eleven Years. Her Balance Went Up By $9,000. Here Is Why
Co-Founder and Chief Data Scientist
Consider a borrower we'll call Maria, a composite of a pattern federal data shows is common. She borrowed about $68,000 for a master's degree, enrolled in an income-driven repayment plan, and paid $412 a month, on time, for eleven years. Nearly $54,000 out of her pocket. When she checked her balance, it read $77,000, which is $9,000 more than she started with.
Nothing went wrong with her payments. What she experienced is negative amortization, and it is a designed feature of how income-driven repayment interacted with interest for most of the past two decades.
The mechanics: when the payment doesn't cover the interest
An income-driven plan sets your payment from your income, not your balance. A $68,000 balance at 6.8% generates roughly $385 in interest every month before touching principal. If your income-based payment is $412, only $27 chips at the principal. If your income dips and the payment recalculates to $250, the unpaid $135 of interest doesn't vanish. It accrues. Month after month, a payment below the interest line means a balance that grows while you pay.
The accelerant: capitalization
Accrued interest is bad; capitalized interest is worse. Capitalization takes the unpaid interest sitting beside your loan and folds it into the principal, so you begin paying interest on your interest. For years, ordinary account events triggered it: leaving a repayment plan, failing to recertify income on time, exiting certain deferments or forbearances. A borrower steered into a year of forbearance during a rough patch, a practice the CFPB repeatedly flagged in servicer supervision, could emerge with thousands capitalized onto the balance. Regulatory changes in recent years eliminated many capitalization triggers on Direct Loans, but the damage from past events is baked into millions of balances, including Maria's.
The fix that arrived, then went away
The SAVE plan, launched in 2023, attacked this problem directly: any interest your calculated payment didn't cover was simply waived, so a SAVE borrower's balance could never grow from unpaid interest. It was the most aggressive negative-amortization fix in the program's history. It was also short-lived: challenged in court, blocked, and then repealed outright, with the plan terminated in 2026 as part of the broader repayment overhaul.
Its successor carries a version of the idea forward. The Repayment Assistance Plan (RAP), which launched July 1, 2026, waives unpaid interest each month and adds a matching benefit toward principal when a low payment doesn't cover interest, at the price of a $10 minimum payment and a 30-year forgiveness horizon. The permanent legacy option, IBR, allows $0 payments at low incomes but has no interest waiver: an IBR balance can still grow exactly the way Maria's did.
What a borrower in this position should check now
First, whether the balance is still growing. Pull your account history and compare monthly interest accrued against your payment. If the payment is below the interest line and you're on IBR or another legacy plan, the growth is ongoing.
Second, which plan the loans are on, and which they can be on. Loans from before July 1, 2026 generally retain access to both IBR and RAP; comparing the two is not about the headline percentage but about your specific number, because IBR can be lower at low incomes while RAP stops the balance from growing. Run both.
Third, the forgiveness clock. This is the part that reframes everything. A growing balance on an IDR plan matters less than it feels like it should, because the endgame is time-based cancellation after 20 or 25 years on legacy plans, not payoff. Maria's eleven years may put her more than halfway to a discharge that erases the entire balance, growth included. The real questions are whether all her months were counted, and the new one for 2026: forgiveness granted from this year onward is federally taxable, so the projected balance at discharge is now also a projected tax bill worth planning for.
A balance that rises while you pay feels like a scam. Mechanically, it's arithmetic, the kind the system spent twenty years allowing, briefly fixed, and has now half-fixed. Knowing which half you're standing in is the whole game.
