Your debt-to-income ratio is the number an underwriter uses to judge whether you can carry a mortgage payment on top of everything else you already owe. The arithmetic is simple. What complicates it is which debts get counted, which income gets used, and how much the answer shifts depending on whether you are applying for a conventional, FHA, VA, or jumbo loan.
How Underwriters Build the Ratio
Debt-to-income compares your total monthly debt obligations to your gross monthly income, meaning income before taxes and deductions. Fannie Mae's Selling Guide describes the ratio as having two components: total monthly obligations, which includes the qualifying payment on the mortgage you are applying for, and the total monthly income of all borrowers to the extent that income is used to qualify (B3-6-02, Debt-to-Income Ratios).
Two versions of the ratio show up in underwriting. The front-end ratio, sometimes called the housing ratio, measures only your proposed housing payment against gross income. The back-end ratio measures your housing payment plus every other qualifying monthly obligation. Conventional underwriting generally evaluates the back-end number. FHA manual underwriting evaluates both, and they are written as a pair, such as 31/43.
An example. On $7,500 of gross monthly income, a proposed housing payment of $2,300 plus a $450 car payment, a $180 student loan payment, and $120 in credit card minimums produces $3,050 in total monthly obligations, or roughly 40.7 percent. The front-end ratio is about 30.7 percent. A debt-to-income calculator will run the same arithmetic on your own figures.
The Debts That Count and the Ones That Usually Do Not
For conventional loans, Fannie Mae's list of what belongs in total monthly obligations is fairly specific:
- The housing payment for each borrower's principal residence, plus the qualifying payment on the subject property if it is a second home or investment property
- Monthly payments on installment debts and other mortgage debts that extend beyond ten months
- Monthly payments on revolving debts, and on lease payments regardless of when the lease expires
- Alimony, child support, or maintenance payments extending beyond ten months, though alimony may instead be deducted from income
- Any net loss from a rental property
Some obligations are treated differently. Installment debts with ten or fewer payments remaining may be left out unless the payment significantly affects your ability to meet credit obligations. Open 30-day charge accounts, which require the balance be paid in full each month, are not required to be included in the conventional calculation under B3-6-05. Things like utilities, groceries, phone bills, and homeowners insurance paid outside the escrowed payment are not treated as debt.
Two qualifications matter. These are conventional rules, and FHA and VA apply their own treatment of student loans, deferred debt, and contingent liabilities, so a debt excluded on one program may be counted on another. A lender may also take a more conservative position than the investor requires, which Fannie Mae permits as long as the approach is applied consistently. If your ratio sits near a threshold, ask how that specific debt will be treated rather than assuming.
Program Limits Sit in Different Places
There is no single mortgage DTI limit. Where the ceiling sits depends on the program, the underwriting method, and the investor buying the loan.
Conventional Loans
Fannie Mae's maximum total DTI on manually underwritten loans is 36 percent. That may be exceeded up to 45 percent when the borrower meets the credit score and reserve requirements in the Eligibility Matrix. For casefiles run through Desktop Underwriter, the maximum allowable ratio is 50 percent. Some transactions carry lower ceilings, including cash-out refinances and loans with non-occupant borrowers.
FHA Loans
HUD does not publish a single maximum ratio for loans evaluated through the TOTAL Mortgage Scorecard, since the scorecard weighs the file as a whole.
Manually underwritten FHA loans follow tiers set in Handbook 4000.1. A minimum decision credit score below 580, or no score at all, is held to 31/43. At 580 and above, 31/43 requires no compensating factors, 37/47 requires one documented factor, and 40/50 requires two.
VA Loans
On VA loans, Pamphlet 26-7 uses 41 percent as a benchmark rather than a hard cap. It points underwriters toward residual income, the dollar amount left each month after taxes, housing, and major debts. Files above 41 percent generally call for residual income that exceeds the applicable guideline by a meaningful margin, along with documented compensating factors.
Jumbo Loans
Jumbo loans are not sold to Fannie Mae or FHA, so the ceiling belongs to whichever investor buys the loan. Guidelines are frequently tighter than conventional, and reserve requirements often do more work than the ratio itself.
A 2026 Update Changed How IRS Payment Plans Are Handled
Fannie Mae Announcement SEL-2026-05, issued May 6, 2026, updated the treatment of federal income tax installment agreements. Where a borrower has an agreement to repay delinquent federal taxes and no federal tax lien has been filed against the subject property, the lender must consider the monthly payment as part of monthly debt obligations.
What the lender needs on file depends on the status of the agreement:
- For an agreement already approved by the IRS, a copy showing the monthly payment and total amount owed, plus evidence that you are current on payments
- For an agreement still pending approval, a copy of the application showing repayment terms, monthly payment, and total owed
- If neither set of documents is available, the balance has to be paid off before or at closing
This is a conventional policy tied to loans delivered to Fannie Mae. It does not automatically carry over to FHA, VA, or jumbo files, and a lender may still apply its own overlay.
FHA has been moving too. HUD published a Handbook 4000.1 update on August 12, 2026 revising employment verification requirements, with a number of revised sections carrying a November 10, 2026 effective date. Verified income is the denominator of your ratio, so documentation changes can move the number even when your debts have not.
Your Ratio Can Move After You Are Approved
An approval is not a frozen snapshot. Under B3-6-02, if you disclose new debt or reduced income, or the lender discovers it, after the underwriting decision and up to closing, the lender must recalculate the ratio.
If the recalculated number exceeds 45 percent on a manually underwritten loan or 50 percent on a Desktop Underwriter casefile, the loan is not eligible for delivery to Fannie Mae. New subordinate financing on the subject property triggers re-underwriting in every case, and the final application you sign has to reflect all income and debts verified, disclosed, or identified during the process.
The division of responsibility is worth understanding. A lender controls how debts are documented, whether it applies overlays stricter than the investor requires, and when a file is resubmitted for a new decision.
A lender does not control the investor's ceilings, the automated underwriting response, or a new account that surfaces when a credit report is refreshed before closing. That last one is why financing furniture or opening a store card between approval and closing can unsettle an otherwise clean file, and it is why underwriters revisit the file rather than treating the first decision as final.
Practical Steps Before You Apply
A few moves tend to matter more than the rest:
- Pay down revolving balances, which lowers the minimum payments that feed the ratio and often moves the number faster than retiring an installment loan
- Coordinate the timing on any installment debt you plan to pay off, since B3-6-07 sets documentation requirements for debts paid at or prior to closing
- Hold off on new accounts and new payments while your file is in process
- Ask what student loan payment figure your program uses, since the calculation differs by program and by repayment status
Two other points are easy to miss. Adding a co-borrower brings their debts along with their income, so the net effect on your ratio may not be what you expect. A larger down payment also helps, since it reduces the housing payment sitting at the top of the calculation.
Reviewing Your Numbers With a Central Florida Lender
At Edge Mortgage USA, we work with buyers and homeowners across Orlando and Central Florida on conventional, FHA, VA, and jumbo financing, and we can walk through how your debts and income would be treated on each. Running the numbers before you shop tends to be more useful than learning mid-contract that a single tradeline changed the answer. Reach out and we will review where your ratio stands and which options fit it.
This article is provided for general educational purposes only and is not financial, legal, or tax advice. Loan program requirements, investor guidelines, and agency policy change over time and are applied based on the specific details of each file, the property, and the terms of your contract. Individual results and eligibility vary. Consult a licensed mortgage professional regarding your circumstances.
