Most people on SSDI pay no federal income tax on their benefits, but some do — and the rule depends on your total income, not just what you receive from Social Security.

Whether your SSDI is taxable comes down to a number called combined income. This is your adjusted gross income plus nontaxable interest plus half of your Social Security benefits. If that number stays below a certain threshold, you owe nothing on your SSDI. If it goes above that threshold, up to 50 percent or 85 percent of your benefits may become taxable.

The thresholds are $25,000 for single filers and $32,000 for married couples filing jointly. These numbers have not changed since 1984, so they catch more people each year as other income rises. If you have a job, a pension, investment income, or a working spouse, you are more likely to cross the line.

Key Takeaways

  • Combined income — not SSDI alone — determines whether your benefits are taxable, and combined income includes half your Social Security benefits themselves.
  • The income thresholds are $25,000 for single filers and $32,000 for married couples filing jointly, and they have not changed since 1984.
  • If you cross the threshold, the IRS taxes either 50 percent or 85 percent of your benefits, depending on how far above the threshold you are.
  • You can reduce combined income by contributing to a traditional IRA, claiming certain deductions, or timing when you receive other income.
  • Social Security sends Form SSA-1099 each January showing your benefits; you report this on your tax return even if you owe no tax.

How the IRS calculates what portion of your SSDI is taxable

The calculation has two tiers. If your combined income exceeds $25,000 (or $32,000 if married filing jointly), you move into the first tier. Here, the IRS taxes the lesser of two amounts: either 50 percent of the amount you are over the threshold, or 50 percent of your total Social Security benefits.

If your combined income exceeds $34,000 (or $44,000 if married filing jointly), you enter the second tier. Now an additional amount becomes taxable: up to 85 percent of benefits above the second threshold. The total taxable amount is the sum of what you owe in both tiers, but it cannot exceed 85 percent of your total benefits.

Example: You are single with $28,000 in combined income and $15,000 in SSDI. You are $3,000 over the first threshold. The IRS calculates 50 percent of $3,000 ($1,500) and compares it to 50 percent of your benefits ($7,500). The lesser amount is $1,500, so $1,500 of your SSDI becomes taxable income.

When you are most likely to owe tax on SSDI

You cross the threshold most often if you have earned income from a job. Even part-time work can push you over, because wages count toward combined income dollar-for-dollar. A spouse's income also counts if you file jointly.

Pensions and retirement account withdrawals count too. If you are under full retirement age and taking early Social Security along with SSDI, both benefits count toward combined income. Investment income — dividends, capital gains, interest — adds up quickly. Rental income and self-employment income also factor in.

Some income does not count: Supplemental Security Income (SSI), workers' compensation, certain veterans' benefits, and some state and local government benefits are excluded. But most other income sources are included in the calculation.

Strategies to reduce your combined income

If you are close to the threshold, a few moves can lower your combined income. Contributing to a traditional IRA reduces your adjusted gross income, which is the starting point for the combined income calculation. The contribution limit for 2024 is $7,000 if you are 50 or older ($6,500 if younger), though you must have earned income to contribute.

Timing matters with other income. If you can defer a bonus, delay a pension payment, or postpone selling an investment until the next tax year, you may stay under the threshold in the current year. Some people stagger large one-time payments across two years for this reason.

If you are married, filing separately instead of jointly sometimes lowers your combined income enough to avoid taxation, though the math is complex and you should check both ways. Married filing separately has its own thresholds ($0 for most people), so this strategy does not always help.

State taxes on SSDI

Thirteen states tax Social Security benefits under their own rules: Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. The rules vary by state — some follow the federal thresholds, others use different income limits, and some exempt SSDI while taxing other Social Security benefits.

If you live in one of these states, you may owe state tax on your SSDI even if you owe no federal tax. Check your state's tax authority website or speak with a tax preparer who knows your state's rules. Some states allow credits or deductions that reduce or eliminate the tax.

Reporting SSDI on your tax return

Social Security mails Form SSA-1099 to you each January. This form shows the total SSDI you received in the previous year. You report this amount on your federal tax return, even if none of it is taxable. The form goes to the IRS as well, so your return must match.

If you have other income, you may file a full Form 1040 or 1040-SR (for people 65 and older). If SSDI is your only income and it is below the filing threshold, you may not have to file at all — but filing can be worth it if you are due a refund from taxes withheld on other income or if you may have access to for the Earned Income Tax Credit or other refundable credits.

Many tax software programs ask about Social Security income and calculate the taxable portion automatically. If you use a tax preparer, bring your SSA-1099 and a list of all other income sources so they can run the combined income calculation correctly.

What happens if you do not report taxable SSDI

The IRS receives a copy of your SSA-1099, so underreporting or omitting your benefits can trigger a notice. If you owe tax and do not pay, the IRS can assess penalties and interest. In some cases, they may offset your tax refund or take other collection action.

If you made an honest mistake, filing an amended return (Form 1040-X) corrects it and usually stops penalties if you act quickly. If you cannot pay what you owe, the IRS offers payment plans and hardship options. Contact the IRS or a tax professional to discuss your situation.

Frequently Asked Questions

Can I reduce my combined income by donating to charity?

Only if you itemize deductions instead of taking the standard deduction. For 2024, the standard deduction is $14,600 for single filers and $29,200 for married couples filing jointly. If your deductions do not exceed these amounts, itemizing does not help. Charitable donations also do not reduce combined income the way a traditional IRA contribution does — they reduce taxable income after combined income is calculated.

Does Medicare or Medicaid count toward combined income?

No. Medicare premiums and Medicaid benefits do not count. However, if you have other income that pays for Medicare premiums, that income does count toward combined income. For example, if you work and earn wages that you use to pay a Medicare premium, the wages count, but the premium itself does not reduce combined income.

What if I am married and my spouse has no income?

Your combined income is still calculated using your household total. If you file jointly, your spouse's lack of income does not lower the threshold — it stays at $32,000. If you file separately, your spouse's return uses a $0 threshold for Social Security taxation, which is usually worse. Filing jointly is normally the better choice in this situation.

Do I have to pay estimated taxes if my SSDI becomes taxable?

Only if you have other income that is not subject to withholding. If you work and have taxes withheld from your paycheck, that withholding may cover your SSDI tax liability. If you have investment income or a pension with no withholding, you may need to make quarterly estimated tax payments. A tax preparer can tell you whether you are required to pay estimated taxes based on your specific situation.

Will my SSDI be reduced if I owe taxes?

No. Owing income tax does not change your SSDI payment amount. You pay the tax separately when you file your return or through estimated payments. However, if you owe back taxes from previous years, the IRS can offset your tax refund or, in rare cases, request that Social Security withhold a portion of your benefits to pay the debt.