How SSDI becomes taxable income

Whether you owe federal income tax on your SSDI depends on your combined income—not just what Social Security sends you. Combined income is the sum of your adjusted gross income, nontaxable interest, and half of your Social Security benefits. If that total crosses a certain threshold, some or all of your SSDI becomes taxable.

The thresholds are $25,000 for single filers and $32,000 for married couples filing jointly. These numbers have not changed since 1984. If your combined income stays below your threshold, you owe no federal tax on your SSDI. If it goes above, you may owe tax on up to 85 percent of your benefits.

The math is not straightforward—the IRS uses a two-tier formula that depends on how far above the threshold you are. Many people find it easier to use the IRS worksheet in Publication 915 or to ask a tax preparer to calculate it for them.

Key Takeaways

  • SSDI becomes taxable only if your combined income (adjusted gross income plus half your benefits) exceeds $25,000 for single filers or $32,000 for married couples filing jointly.
  • Combined income includes wages, self-employment income, pensions, interest, dividends, and other sources—not just SSDI.
  • If you are over the threshold, the IRS uses a two-tier formula to determine what percentage of your benefits are taxable, up to a maximum of 85 percent.
  • Social Security sends you a Form SSA-1099 each January showing your annual benefits; you use this to report SSDI on your tax return.

What counts toward the combined income threshold

Combined income is wider than you might think. It includes your wages from work, self-employment income, pensions, interest from savings accounts and bonds, dividends from stocks, rental income, and income from a spouse if you file jointly. It also includes certain distributions from retirement accounts and some distributions from trusts.

What it does not include: Supplemental Security Income (SSI), workers' compensation, veterans' benefits, or certain railroad retirement benefits. If you receive any of those alongside SSDI, they do not push you over the threshold.

The reason combined income matters is that Congress wanted to tax SSDI only for people with other substantial income. Someone living on SSDI alone will never owe federal tax on it. Someone with SSDI plus a part-time job, a pension, or investment income may.

The two-tier tax formula explained

If your combined income exceeds the threshold, the IRS does not automatically tax 85 percent of your benefits. Instead, it uses two tiers. The first tier taxes up to 50 percent of your benefits. The second tier taxes up to an additional 35 percent.

The first tier applies to the amount your combined income exceeds the threshold, up to $9,000 (for single filers) or $12,000 (for married couples filing jointly). If your excess combined income is $5,000, you may owe tax on up to $2,500 of your benefits—half of the excess.

The second tier applies to combined income above those amounts. If your excess combined income is $15,000, the first $9,000 is taxed at the 50 percent rate, and the remaining $6,000 is taxed at the 35 percent rate. This is why the maximum taxable portion is 85 percent—it is the sum of the two tiers.

The IRS worksheet in Publication 915 walks through this step by step. If the math feels overwhelming, a tax preparer or the AARP Tax-Aide program (free for people over 60) can calculate it for you.

How to report SSDI on your tax return

In January, Social Security mails you a Form SSA-1099 showing the total SSDI you received in the previous year. You use this form to report your benefits on your federal tax return. The form goes to Box 5 of your Form 1040 or 1040-SR.

If you use tax software, you enter the amount from Box 5 of your SSA-1099, and the software calculates whether any of it is taxable based on your other income. If you file by hand, you use the worksheet in Publication 915 to determine the taxable amount, then report that on line 5b of your Form 1040.

You must report SSDI even if none of it is taxable. Failing to file when you have SSDI income can trigger a notice from the IRS, even if you ultimately owe no tax.

State and local taxes on SSDI

Most states do not tax SSDI. However, a handful of states—Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, and Vermont—tax some or all of it under certain conditions.

The rules vary by state. Some states follow the federal threshold; others have their own. Some states exempt SSDI entirely if your income is below a certain level. A few states tax SSDI the same way they tax other income.

If you live in one of these states, contact your state tax authority or a local tax preparer to understand your state's rules. Your state's department of revenue website usually has a publication on Social Security taxation.

What to do if you think you will owe tax

If you know your combined income will exceed the threshold, you have options. You can make estimated tax payments to the IRS throughout the year, or you can ask Social Security to withhold federal income tax directly from your SSDI checks.

To request withholding, fill out Form W-4V and send it to your local Social Security office or mail it to Social Security. You can choose to have 10 percent, 15 percent, 20 percent, or 25 percent of your benefit withheld each month. This does not change the amount of tax you owe—it just spreads the payment across the year so you do not owe a large amount when you file.

If you do not withhold and do not make estimated payments, you may owe a penalty when you file your return. The penalty is small if the amount owed is small, but it adds up if you owe a significant tax bill.

Frequently Asked Questions

Can I avoid taxes on SSDI by not reporting other income?

No. The IRS calculates combined income from all sources, whether you report them or not. If you have wages, the IRS receives a W-2 from your employer. If you have interest or dividends, banks and investment firms report them. Underreporting income creates a mismatch that triggers an audit.

Does working part-time while on SSDI automatically make my benefits taxable?

Not automatically. It depends on how much you earn. If your wages plus half your SSDI stay below the threshold, your benefits are not taxable. A part-time job earning $500 a month may not push you over, but a full-time job will.

What if I receive SSDI for only part of the year?

Social Security reports only the months you actually received benefits on your SSA-1099. If you started SSDI in June, the form shows only six months of payments. You use that actual amount to calculate combined income and determine if any is taxable.

Can I deduct medical expenses to lower my taxable SSDI?

Medical expenses do not reduce combined income for SSDI tax purposes. You can deduct medical expenses on Schedule A only if you itemize deductions and they exceed 7.5 percent of your adjusted gross income. This is separate from the SSDI tax calculation.

What happens if I owe tax but cannot pay it all at once?

The IRS offers payment plans. You can request an installment agreement by calling 1-800-829-1040 or setting one up online at IRS.gov. You will owe interest and a setup fee, but a payment plan prevents penalties from growing larger.