SSA-1099 Explained: How Much of My 2026 Social Security Is Taxable?
Enter box 5 and box 6 of your SSA-1099 and your other 2026 income. The tax engine behind the 2026 Return Preview works out the taxable part for line 6b, the federal tax your benefits add, and whether box 6 covers it.
How the next dollar of income makes more of your benefits taxable: the Social Security tax calculator. Your IRA and pension statement: Form 1099-R explained.
What do I do with my SSA-1099, and how much of it is taxable?
The SSA-1099 is the Social Security Administration’s statement of the benefits you were paid in 2026. Box 5, your net benefits (box 3, benefits paid, minus box 4, benefits you repaid), goes on Form 1040 line 6a, and the taxable part goes on line 6b (IRS Publication 915). Up to 85% of it can be taxable, depending on your other income: none of it is taxable while half of your benefits plus your other income and tax-exempt interest stays at or under $25,000 ($32,000 married filing jointly), and the share rises above that (IRC §86). Box 6 is the federal income tax withheld from your benefits under a Form W-4V; it goes on line 25b with your other 1099 withholding (Form 1040 instructions). Medicare premiums taken out of your benefits are listed in the box 3 description; do not subtract them from box 5 (IRS Publication 915). Example: a married couple, 69 and 67, with $42,000 in box 5, a $30,000 pension, $15,000 of IRA withdrawals and $2,000 of interest have $26,400 of taxable benefits on line 6b, 62.9% of box 5; the benefits add $2,615 to their federal tax of $2,615, and the $2,940 in box 6 (7% withheld) leaves them a refund of $325.
| Key number | 2026 |
|---|---|
| Box 5 (net benefits) → Form 1040 line 6a (IRS Publication 915) | all of it |
| Taxable part → line 6b (§86) | up to 85% |
| None taxable while ½ of benefits + other income + tax-exempt interest is at most (Pub. 915) | $25,000 / $32,000 joint |
| Box 6 (federal tax withheld) → line 25b (Form 1040 instructions) | withholding |
| Example: taxable benefits (line 6b) | $26,400 |
| Example: share of box 5 taxable | 62.9% |
| Example: federal tax (Tax Table) | $2,615 |
| Example: federal tax the benefits add | $2,615 |
| Example: refund with $2,940 in box 6 | $325 |
| Example: North Carolina tax (benefits not taxed) (North Carolina rules) | $858 |
Your benefits are two lines of the return; the rest of it decides the refund: 2026 tax return calculator (free: your federal and state refund or amount owed) →
An estimate from QuantCalc’s open tax engine (federal 2.3.1, state 1.14.2) for the 2026 tax year. Not tax advice: your return depends on facts this page does not ask about, so check a move with your tax preparer or custodian before acting. How the engine computes each line, with its official source: federal, state.
Enter your own SSA-1099 below.
Your SSA-1099 on your 2026 return
Your benefits with every other line of the return, and the refund or amount owed: 2026 Return Preview: every Form 1040 line, your state and your refund or amount owed →
An estimate from QuantCalc’s open tax engine (federal 2.3.1, state 1.14.2) for the 2026 tax year. Not tax advice: your return depends on facts this page does not ask about, so check a move with your tax preparer or custodian before acting. How the engine computes each line, with its official source: federal, state.
The SSA-1099 box by box
| Box | What it shows | On your return |
|---|---|---|
| Box 3 | Benefits paid to you in 2026, before Medicare premiums and other amounts withheld | Not entered; box 5 is |
| Box 4 | Benefits you repaid to the SSA in 2026 | Already subtracted in box 5 |
| Box 5 | Net benefits: box 3 minus box 4 | Line 6a; its taxable part on line 6b |
| Box 6 | Voluntary federal income tax withheld (Form W-4V) | Line 25b |
| Description of amount in box 3 | Medicare Part B, C and D premiums deducted, and other adjustments | Not subtracted from box 5 |
Married filing jointly: add both spouses’ box 5 amounts. If your box 5 is negative because you repaid more than you received, none of your benefits are taxable for 2026 (IRS Publication 915). North Carolina, like most states, does not tax Social Security: in the example the couple’s state tax, $858, is the same with or without their benefits (North Carolina rules).
Common questions
- Which SSA-1099 box do I use on my tax return?
- Box 5, net benefits, on Form 1040 line 6a; the taxable part on line 6b. Box 6, any federal tax withheld, goes on line 25b (IRS Publication 915; Form 1040 instructions).
- How much of my Social Security is taxable in 2026?
- Between 0% and 85%, depending on your other income. In the example, 62.9% of $42,000 ($26,400) is taxable for a married couple with a $30,000 pension and $15,000 of IRA withdrawals (IRC §86).
- Why does my SSA-1099 show more than I received?
- Box 3 is before Medicare premiums and other amounts taken out of your payments; those deductions are listed in the description of box 3. Use box 5 as it is, without subtracting them (IRS Publication 915).
- What is box 6 on the SSA-1099?
- Federal income tax withheld from your benefits because you asked for it on Form W-4V: 7%, 10%, 12% or 22% of each payment. It counts as tax paid on line 25b.
- How do I get a copy of my SSA-1099?
- A replacement Form SSA-1099 for any of the past 6 years can be downloaded from a my Social Security account at SSA.gov/myaccount (IRS Publication 915).
- Does the new senior deduction make my Social Security tax-free?
- No. The taxable part on line 6b is figured the same way as before; the $6,000 senior deduction for people 65 or older lowers taxable income on Schedule 1-A instead. See the senior deduction calculator.