© Fannie Mae Single Family Selling Guide

DTI Ratios

The DTI ratio consists of two components:

• total monthly obligations, which includes the qualifying payment for the subject mortgage loan and other long-term and significant short-term monthly debts (see Calculating Total Monthly Obligation below); and
• total monthly income of all borrowers, to the extent the income is used to qualify for the mortgage (see Chapter B3–3, Income Assessment).

Maximum DTI Ratios

For manually underwritten loans, Fannie Mae's maximum total DTI ratio is 36% of the borrower's stable monthly income. The maximum can be exceeded up to 45% if the borrower meets the credit score and reserve requirements reflected in the Eligibility Matrix. 

For loan casefiles underwritten through DU, the maximum allowable DTI ratio is 50%. If the DTI on a loan casefile exceeds 50%, the loan casefile will receive an Ineligible recommendation.

Exceptions to the Maximum DTI Ratio

Fannie Mae makes exceptions to the maximum allowable DTI ratios for particular mortgage transactions, including:

• DU Refi Plus and Refi Plus — may exceed the maximum ratios above except for certain Refi Plus transactions that have a maximum DTI ratio requirement. See B5-5.2-02, DU Refi Plus and Refi Plus Underwriting Considerations (09/[ 26/2017)|B5-5.2-02, DU Refi Plus and Refi Plus Underwriting Considerations (09_ 26_2017)], for additional information;
• borrowers who do not have a credit score — the maximum ratio may be lower for manually underwritten loans and DU loan casefiles (see B3-5.4-01, Eligibility Requirements for Loans with Nontraditional Credit (12/19/2017));
• non-occupant borrowers — the maximum ratio is lower than 45% for the occupying borrower for manually underwritten loans (see B2-2-04, Guarantors, Co-Signers, or Non-Occupant Borrowers on the Subject Transaction (06/05/2018)); and
• government mortgage loans — lenders must follow the requirements for the respective government agency.

Calculating Total Monthly Obligation

The total monthly obligation is the sum of the following:

• the monthly housing expense of the borrower's principal residence (or the qualifying payment amount if the subject mortgage loan is secured by the borrower's principal residence (see B3-6-03, Monthly Housing Expense (05/28/[ 2013)|B3-6-03, Monthly Housing Expense (05_28_2013)]));
• the qualifying payment amount if the subject mortgage loan is secured by a second home or investment property (see B3-6-04, Qualifying Payment Requirements (04/15/2014));
• monthly payments on installment debts and other mortgage debts that extend beyond ten months;
• monthly payments on installment debts and other mortgage debts that extend ten months or less if the payments significantly affect the borrower's ability to meet credit obligations;
• monthly payments on revolving debts;
• monthly payments on lease agreements, regardless of the expiration date of the lease;
  monthly alimony, child support, or maintenance payments that extend beyond ten months (alimony (but not child support or maintenance) may instead be deducted from income, see B3-6-05, Monthly Debt Obligations (01/30/2018);
• monthly payments for other recurring monthly obligations; and
• any net loss from a rental property.

Note: Fannie Mae acknowledges that lenders may sometimes apply a more conservative approach when qualifying borrowers. This is acceptable as long as Fannie Mae's minimum requirements are met, and lenders consistently apply the same approach to similar loans. For example, a lender might calculate a higher minimum payment on a credit card account than what Fannie Mae requires, which is acceptable as long as the lender consistently applies this calculation to all mortgage applications with revolving debts.

DTI Ratio Tolerance and Re-Underwriting Criteria

Fannie Mae expects lenders to have in place processes to facilitate borrower disclosure of changes in financial circumstances throughout the origination process and prefunding quality control processes to increase the likelihood of discovering material undisclosed debts or reduced income. See D1-2-01, Lender Prefunding Quality Control Review Process (03/28/2017).

As a result of the lender's normal processes and controls, the lender may need to re-underwrite the loan after initial under- writing. If the borrower discloses or the lender discovers additional debt(s) or reduced income after the underwriting decision was made up to and concurrent with loan closing, the loan must be re-underwritten if the new information causes the DTI ratio to increase by 3 or more percentage points up to the maximum allowed.

In all cases, if the lender determines that there is new subordinate financing on the subject property during the loan process, the mortgage loan must be re-underwritten.

Note: Re-underwriting means that loan casefiles must be resubmitted to DU with updated information; and for manually underwritten loans, a comprehensive risk and eligibility assessment must be performed.

Applying the Re-underwriting Criteria

The following steps are required if the borrower discloses or the lender discovers additional debt(s) or reduced income after the underwriting decision was made up to and concurrent with loan closing:

For additional information about DU resubmission tolerances, see B3-2-10, Accuracy of DU Data, DU Tolerances, and Errors in the Credit Report (07/25/2017).