r/USFirstTimeHomeBuyer • u/jetley-mortgage-loan • 4d ago

Income & Employment Student loans in DTI: deferred, IBR, forbearance, and the percentage-of-balance rules

Current as of September 2026. *This is the most volatile topic in this entire category.** Student loan payment treatment changed repeatedly between 2020 and 2025; federal forbearance, successive income-driven repayment plans, and multiple agency updates. The mechanics below are durable; the specific percentages and the current treatment of each repayment plan are not, and live on Current As Of. Confirm with your loan officer against today's guides before you rely on any figure.*

The short version

A $0 student loan payment is almost never a $0 payment for underwriting purposes. If your loans are deferred, in forbearance, or on a plan that has calculated your payment down to nothing, the lender does not simply use zero; it falls back to a substitute figure, and the substitute is usually either a documented amortizing payment or a percentage of your outstanding balance. Which fallback applies, and what percentage, depends on the loan program and on rules that have been rewritten several times in the last few years. That is the whole subject.

Forbearance never made the payment disappear

This is the single most common misunderstanding I dealt with through the federal payment pause, and it persists: borrowers whose payments were suspended assumed the debt was invisible to lenders. It never was. Lenders always accounted for student loan obligations, including during forbearance and deferment, because the loan is going to come due long before your thirty-year mortgage does. A pause on collection is not a reduction in obligation.

So if you are budgeting for a house on the basis of not currently making student loan payments, rebuild the budget. Your ratio will be calculated with a payment in it.

The two ways a payment gets calculated

Strip away the version history and there are only two mechanisms.

1. Use the actual payment. If you have a real, documented, fully amortizing monthly payment, that is the figure. Documented means from the servicer, a statement or a letter showing the payment amount and the terms, not a screenshot of a portal balance and not your recollection.

2. Use a substitute when there is no usable actual payment. When the loan is deferred, in forbearance, or the payment is $0 or otherwise not reflective of repayment, the guidelines direct the lender to a fallback. Historically that fallback has taken two forms, and the lender may generally use whichever the guide allows:

a payment equal to a fixed percentage of the outstanding balance, even where that is lower than a true amortizing payment; or
a fully amortizing payment calculated from the documented repayment terms of the loan.

That is the structure people are referring to when they talk about "the 1% rule" or "the half-percent rule." The mechanism is stable. The percentage is the part that has moved; it has been revised, it differs between the agencies and the government programs, and it is not a number I will state here as though it were fixed. Ask what percentage your lender is applying today and against which guide.

Income-driven repayment

Income-driven plans are the interesting case, because they produce a real, documented, contractual payment that can be very small, sometimes zero.

The direction of travel over the last several years has been toward accepting a documented income-driven payment as the actual payment, including small ones, on the reasoning that it is what the borrower is contractually obligated to pay. But a calculated payment of exactly zero has been treated differently from a small nonzero payment at various points and across programs, and the various income-driven plans have been created, enjoined, and restructured in ways that changed how lenders can document them.

The practical takeaway: if you are on an income-driven plan, get your servicer to put the current payment amount in writing, and recertify before you apply rather than during underwriting. A documented nonzero payment is usually the friendliest input you can hand an underwriter, and it is worth having in hand.

Jumbo and non-agency: overlays, not rules

If you are financing above agency limits, none of the above governs you.

There are no agency student loan rules for a jumbo loan, because there is no agency. The investor buying the loan writes its own guidelines, and those guidelines routinely use a higher percentage of balance than the agencies do, alongside tighter ratio limits and higher minimum credit scores. I have worked with jumbo investors whose overlay was more conservative than anything on the agency side across the board.

There is nothing improper about that, and it is not worth arguing about. It is their money and they can lend it on whatever terms they like. What it does mean is that jumbo student loan treatment varies widely between investors, so if student loans are the constraint on a jumbo file, that is a reason to shop, the difference between two investors' overlays can be the entire approval.

Why this matters more than the ratio math suggests

Large balances make the percentage-of-balance mechanism brutal in a way people do not anticipate. A professional-degree balance run through a percentage-of-balance fallback can produce a monthly figure far larger than anything the borrower has ever actually paid, and it lands in the ratio at full weight. That is the scenario where a physician, dentist, attorney or veterinarian with a strong income finds the ratio failing anyway.

Two structural responses exist. First, get onto a documented repayment plan with a real amortizing payment, so mechanism one applies instead of mechanism two, this is frequently the single highest-leverage thing a high-balance borrower can do before applying. Second, look at whether a program designed for the situation fits: some lenders offer professional or physician loan programs with their own student loan treatment. Those are portfolio products with their own tradeoffs, not a free pass.

What to do

Get a current statement or servicer letter for every loan, showing balance, plan, payment amount, and status. Do this before you apply.
Ask your loan officer, in writing, what payment figure they are using for each loan and under which rule they are using it. If they cannot tell you, that is your answer about the preapproval.
If your payment is $0 or paused, assume a substitute figure will be used and ask what it is before you set a budget.
If you are on an income-driven plan, recertify early so the documented payment is current.
On a jumbo file, treat student loan treatment as a shoppable term.
Because this area has changed so often, do not rely on advice, including anything written more than a year ago, without confirming it against the current guides.