Conventional Loan Documentation for Grossing Up Social Security Income

The Quick Read: Grossing up means a lender adds an adjustment to the nontaxable part of your Social Security benefit when it counts your income. It changes the income side of your debt-to-income ratio. It does not change your deposit or your payment. The file needs proof of the benefit, proof it will continue, and proof of how much of it is nontaxable.

What Does “Grossing Up” Actually Do?

Grossing up raises qualifying income, not real income. Lenders figure income as if it were all taxed. Nontaxable income is worth more than taxable income of the same size, so the lender adds to it.

Fannie Mae’s Selling Guide, B3-3.1-01 says that when income is verified as nontaxable and likely to continue, the lender should add an amount equal to 25% of the nontaxable income. If taxes on a wage earner in a similar bracket would run higher than 25%, the lender may use that larger amount.

The adjustment works on the income side of the debt-to-income ratio. The benefit is unchanged. Your bank deposit stays the same, and so does your monthly budget.

Plan around what lands in your account. The grossed-up figure is a yardstick for the lender, not spending money.

Does the 25% Apply to the Whole Benefit?

No. This is the most common misunderstanding. The 25% applies to the nontaxable portion, and for most borrowers that portion is only a slice of the benefit.

Fannie Mae Selling Guide Announcement SEL-2023-11 clarified that lenders may treat 15% of Social Security income as nontaxable. Secondary summaries of the Freddie Mac and Fannie Mae examples apply the 25% adjustment to that 15% slice. A $1,000 benefit would give $150 nontaxable, a $37.50 adjustment, and $1,037.50 in qualifying income. That is not $1,250.

Treat that worked example as illustrative. Confirm the 15% treatment in the live Guide text for your lender’s file before you rely on it. Borrowers who want a larger share treated as nontaxable generally need documents showing the actual nontaxable amount, usually the most recent individual tax return.

In practice, the adjustment helps a file at the margin. It can nudge a borderline file over the line. It will not rescue a file that is far over the limit.

Which Social Security Benefits Count?

Retirement, disability, survivor or dependent benefits, and SSI can all appear in a file. The benefit type and whose earnings record it sits on decide what paperwork you need and how continuance is tested.

• Retirement benefits on your own record. These are the simplest. They usually have no defined end date.
• Disability benefits. Documentation options are spelled out in both agency guides, and continuance may be reviewed.
• Survivor or dependent benefits. These are often paid on another person’s record. They can carry a defined end date, such as a child aging out.
• SSI. The IRS says SSI payments are not Social Security benefits for tax purposes and are not taxable. How each agency treats SSI for the gross-up should be confirmed in the live Guide.

What Documents Does a Conventional File Need?

Expect to document three things: that you receive the benefit, how much it is, and that it will continue. The first two usually come from the same paperwork.

Fannie Mae’s Social Security income section, B3-3.4-15 requires evidence of regular receipt. What counts depends on the benefit type and whether you are the owner of the record or someone else. An SSA award letter may be used if you already receive payments, or will start on or before the first payment date of the new mortgage, as shown by a recently issued letter.

Fannie Mae announcement SEL-2022-09 added the SSA-1099 and signed federal traditional personal-income documentation or transcripts as options for retirement and disability benefits. Freddie Mac’s Guide Section 5305.1 lets the seller choose among the SSA benefit verification letter, the most recent IRS Form 1099-SSA, or pages 1 and 2 of the latest federal return (pages 1 through 3 for a 1040-SR).

Across the wholesale conventional programs we place files with, the award letter plus recent bank statements is the common starting package. Order the letter early. A stale one is the usual reason a condition comes back.

How Is the Gross-Up Underwritten, Step by Step?

The sequence is the same on most files. Here is how it runs.

1. Identify the benefit type and record owner. Retirement, disability, survivor, or SSI, and whose record it is.

2. Collect the documents. Award letter or benefit verification letter, SSA-1099, traditional personal-income documentation or transcripts, and proof of current receipt.

3. Confirm continuance. Own-record retirement benefits are generally expected to continue. Benefits paid on another person’s record may need evidence of a remaining period. Confirm the exact test in the live Guide.

4. Determine the nontaxable portion. The lender either uses the presumed 15% slice or relies on your return to show a larger documented portion.

5. Apply the adjustment. The 25% goes on the nontaxable amount, or a higher tax-based figure where the guide allows it.

6. Add it to qualifying income. Only the income side of the ratio changes.

7. Run the automated underwriting. Fannie Mae’s or Freddie Mac’s system weighs the adjusted income with credit, assets, and debts.

The gross-up has no direct effect on the appraisal. The appraisal sets value, loan-to-value, and mortgage insurance. Income sets the ratio. They meet only through the final loan amount and payment.

Default Slice or Documented Larger Portion?

Most borrowers take the default slice and move on. A larger documented portion matters mainly when the file is tight and the tax return clearly shows more of the benefit is nontaxable.

Here is the decision in plain terms.

• No tax return in the file, or no need for more. The lender uses the presumed slice. No tax documents are needed for that slice.
• Tax return available and the file needs more room. The return shows what portion of the benefit was nontaxable. The lender can use that documented amount instead.
• Higher income households. If other income makes much of the benefit taxable, the nontaxable portion is small. The presumed slice may still apply, but a larger gross-up is unlikely.

Whether any benefit is taxable is a tax question. Tax treatment can depend on your situation; borrowers should speak with a qualified tax professional before relying on any deduction or credit. The IRS explains the basics in Publication 915.

What if the Documents Don’t Match?

Mismatches are common and fixable. The letter shows one figure, and the deposit shows another, usually because of deductions such as Medicare premiums withheld before payment.

• Deposit lower than the letter. The letter generally shows the gross benefit. Underwriters often reconcile the difference with the deduction shown on the statement. Keep the letter and a recent statement together so the gap is explained.
• Old letter or a recent cost-of-living change. Request a current letter. A recently issued one is what the agency guide points to.
• Joint tax return with someone who is not a borrower. Under Freddie Mac 5305.1, the seller needs extra documentation supporting the Social Security amount used.
• Benefit not yet started. The award letter can still work if payments begin on or before the first payment date of the new mortgage.

Mixed-Income and Two-Borrower Files

Each income stream follows its own rules. Only the Social Security portion is grossed up. If one borrower has wages and the other has benefits, the wages are documented the usual way and the benefit takes the path above.

On a survivor file, the question is whose record and whose return. A pension, IRA, or wage income shifts how much of the benefit is taxable, and that changes the nontaxable portion on the return.

A spouse’s income does not change the other spouse’s gross-up. It can change the tax picture that supports a larger documented amount.

Where the Rules Break

A few cases do not follow the general pattern.

• Fannie Mae and Freddie Mac differ. They are broadly aligned. Section numbers, document menus, and treatment of higher gross-ups are not identical. Don’t assume one lender’s checklist matches the other.
• FHA, VA, and USDA. Other programs set their own percentages. A conventional rule should not be carried over to them.
• Occupancy. The gross-up concerns income. Occupancy affects other terms. On a purchase, a principal residence generally allows more leverage than a second home or an investment property.
• Continuance on non-retirement benefits. Defined end dates need evidence of how long the benefit will run.

Under Regulation B, a creditor must evaluate retirement and public-assistance income individually. It may not automatically discount or exclude protected income. Lenders can still verify the amount and continuance.

How This Fits With the Rest of the Conventional Loan

Grossing up only moves the income number. The rest of the file still applies. On a purchase, conventional financing on a principal residence reaches 97% loan-to-value for a first-time buyer with a fixed rate, and 95% otherwise. Mortgage insurance is required above 80% and can be cancelled at 80% of the original value on request. The servicer must end it automatically at 78%.

For the credit side, the wholesale conventional programs start at a 620 decision score. The automated finding governs most files, with a total ratio ceiling of 50%. A modest gross-up can matter when the ratio sits near that line. All of these are subject to lender guidelines and full file review.

Lendmire arranges conventional loan programs through wholesale lenders in 16 states, so one file can be compared across more than one lender.

If you are already retired and thinking about tapping equity later, Lendmire’s piece Conventional Cash-Out Requirements for Pension and Social Security Income covers that separate path.

Key Terms Defined

Gross-up: An adjustment that adds to the nontaxable part of income so it compares fairly with taxable income.

Nontaxable income: Income, or the part of it, on which no federal income tax is owed.

Debt-to-income ratio (DTI): Your monthly debts divided by your monthly qualifying income.

Continuance: Evidence that an income stream will keep coming for the loan’s early years.

Award letter: The SSA letter stating benefit type and amount.

SSA-1099: The annual statement of Social Security benefits paid.

Borrower Checklist

• Current SSA award letter or benefit verification letter
• Most recent SSA-1099
• Recent federal traditional income documentation or transcripts, if available
• Recent bank statements showing deposits
• Notes on any deductions such as Medicare premiums
• Evidence of continuance if the benefit is on another person’s record

Common Mistakes

• Expecting a 25% increase on the whole benefit.
• Budgeting on the grossed-up number instead of the deposit.
• Submitting an old award letter.
• Forgetting that a joint return with a non-borrower needs extra support.
• Assuming FHA or VA treat it the same way.

If you are buying a home and want to see whether a conventional loan fits your file, Lendmire can help you compare the options and what each one asks of the file. Program details are subject to lender guidelines and full file review, and nothing here is a commitment to lend.

For your own numbers, request a scenario review with Lendmire.

About Lendmire

Lendmire, NMLS# 2371349, is a mortgage brokerage with consumer lending licenses in 16 states. FHA, VA, conventional and jumbo purchase and refinance loans are arranged through wholesale lending partners, and each application is reviewed individually by the lender. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.

References

1. Fannie Mae Selling Guide B3-3.1-01, General Income Information

2. Fannie Mae Selling Guide Announcement SEL-2023-11

3. Fannie Mae Selling Guide B3-3.4-15, Social Security Income

4. SEL-2022-09

5. Freddie Mac Guide Section 5305.1

6. Publication 915

7. Regulation B, 12 CFR Part 1002 (eCFR)