Missouri follows federal tax rules for SSDI, not its own separate state tax

Missouri does not tax Social Security Disability Insurance (SSDI) benefits at the state level. If you receive SSDI in Missouri, you will not owe state income tax on those benefits, regardless of how much you earn or what your total household income is.

However, your SSDI benefits may still be subject to federal income tax. The federal government uses a formula based on your "combined income" to decide whether any portion of your SSDI is taxable. Missouri's decision to exempt SSDI from state tax does not change what you owe to the IRS.

This distinction matters because you could owe federal tax on SSDI while owing nothing to Missouri. You will need to file both a federal return (Form 1040) and a Missouri state return (Form MO-1040) if your income crosses certain thresholds, but only the federal return will include SSDI in the taxable calculation.

Key Takeaways

  • Missouri does not tax SSDI benefits at the state level, so you will not owe Missouri income tax on SSDI alone.
  • Federal tax on SSDI depends on your combined income (SSDI plus half your SSDI plus other income), not on Missouri's rules.
  • You may owe federal tax on SSDI while owing nothing to Missouri, so you need to calculate both separately.
  • If you work while receiving SSDI, your wages are taxed by both Missouri and the federal government, but your SSDI portion is only federally taxable.

How federal tax on SSDI is calculated

The IRS uses a two-tier system to determine whether your SSDI is taxable at the federal level. Your "combined income" is calculated as your adjusted gross income plus nontaxable interest plus half of your SSDI benefits. If that combined income exceeds certain thresholds, a portion of your SSDI becomes taxable.

For the 2024 tax year, if you are single and your combined income is between $25,000 and $34,000, up to 50 percent of your SSDI may be taxable. If your combined income exceeds $34,000, up to 85 percent may be taxable. If you are married filing jointly, the thresholds are $32,000 and $44,000. These thresholds do not change year to year, so they have not increased since 1984.

Missouri's state tax system does not use these federal thresholds. Because Missouri exempts SSDI entirely, you do not calculate combined income for Missouri purposes. You only report wages, interest, dividends, and other non-SSDI income to Missouri.

What counts as income for the federal SSDI tax calculation

Combined income includes more than just SSDI and wages. It also includes interest from savings accounts and bonds, dividends from stocks, capital gains from selling property, rental income, and income from self-employment. It even includes nontaxable interest from municipal bonds, which most people do not think of as "income."

Importantly, combined income includes half of your SSDI benefits even though that half is not itself taxable. This is why someone with modest other income can end up with SSDI that is partially taxable. If you receive $1,500 per month in SSDI ($18,000 per year) and have $10,000 in other income, your combined income is $10,000 plus $9,000 (half of SSDI), which equals $19,000. That is below the $25,000 threshold for a single filer, so none of your SSDI is taxable.

But if you have $20,000 in other income, your combined income becomes $20,000 plus $9,000, which equals $29,000. Now you are in the first tier, and up to 50 percent of your SSDI becomes taxable. The IRS will tax up to $9,000 of your $18,000 SSDI benefit.

SSDI and Missouri state tax filing requirements

Missouri requires you to file a state return if your Missouri taxable income exceeds a certain threshold. For 2024, that threshold is $1,250 for a single filer under age 65, and $2,050 for a single filer age 65 or older. Because SSDI is not included in Missouri taxable income, you only count wages, interest, dividends, and other non-SSDI sources.

This means you could have substantial SSDI income and still have no Missouri filing requirement. If you receive $2,000 per month in SSDI ($24,000 per year) and no other income, you do not have to file a Missouri return. You would still file a federal return if your combined income triggers the federal threshold, but Missouri would not require a state return.

If you work while receiving SSDI, your wages are counted toward the Missouri filing threshold. Wages are also included in the federal combined income calculation, which determines whether your SSDI is federally taxable. So work income affects both your state and federal tax situation, but in different ways.

Work incentives and how they interact with Missouri taxes

SSDI includes work incentives that allow you to earn money without when ready losing your benefit. The most common is the Trial Work Period, which lets you earn any amount for nine months without affecting your SSDI payment. During this period, you still receive your full SSDI benefit.

Wages you earn during the Trial Work Period are subject to both Missouri and federal income tax. They count toward the Missouri filing threshold and toward your federal combined income. However, they do not reduce your SSDI payment, so you receive both your full benefit and your wages.

After the Trial Work Period ends, SSDI uses a different calculation called Substantial Gainful Activity (SGA). In 2024, SGA is $1,550 per month for non-blind workers. If you earn more than that, your SSDI can be suspended. But during months when you earn less than SGA, you still receive your full benefit, and those wages are still taxable by both Missouri and the federal government.

Medicare and Medicaid do not change Missouri's SSDI tax treatment

SSDI automatically qualifies you for Medicare after 24 months of receiving benefits. Medicare premiums are deducted from your SSDI payment, but those premiums do not reduce your taxable SSDI income. The IRS taxes the full SSDI amount, not the amount after Medicare is deducted.

Missouri's Medicaid program (called MO HealthNet) is separate from SSDI. You may be on both programs, but Medicaid does not affect whether your SSDI is taxable to Missouri (it is not) or to the federal government (it may be, depending on combined income). Medicaid is a needs-based program, and your SSDI counts toward your income for Medicaid purposes, but that is a different calculation from tax.

How to report SSDI on your Missouri and federal returns

The Social Security Administration sends you a Form SSA-1099-Soc Sec each January showing your total SSDI for the previous year. You use this form to complete both your federal and Missouri returns.

On your federal return (Form 1040), you report your SSDI on lines 5a and 5b. Line 5a is the total SSDI you received. Line 5b is the taxable portion, which you calculate using the federal combined income formula or by using the IRS worksheet. If none of your SSDI is taxable, you enter zero on line 5b.

On your Missouri return (Form MO-1040), you do not report SSDI at all. You only report wages, interest, dividends, and other non-SSDI income. This is why your Missouri return is often simpler than your federal return, even though you received substantial SSDI income.

Frequently Asked Questions

Do I have to file a federal return if I only receive SSDI and have no other income?

No, if SSDI is your only income, you generally do not have to file a federal return because your income is below the filing threshold. However, if you are due a refund (for example, if taxes were withheld from other income), filing a return allows you to claim it. You can also file to claim the Earned Income Tax Credit if you have wages.

What if I receive both SSDI and SSA retirement benefits?

Both SSDI and Social Security retirement benefits use the same federal tax formula. Your combined income includes both benefits (you count half of the total of both), and the same thresholds explore. Missouri taxes neither one. If you receive both, add them together when calculating your combined income for federal purposes.

Can I claim SSDI as a dependent on someone else's return?

SSDI does not count as income for the purpose of determining whether you can be claimed as a dependent. The test is whether you provide more than half your own support, not whether you have income. If someone else provides more than half your support and you meet other tests, they can claim you as a dependent even though you receive SSDI.

Does Missouri tax SSDI if I move there from another state?

No. Missouri's exemption of SSDI from state tax applies to all residents, regardless of where they lived before. Once you establish residency in Missouri, your SSDI is not subject to Missouri income tax. However, you may still owe federal tax on SSDI depending on your combined income.

What if I disagree with the IRS about how much of my SSDI is taxable?

You can contact the IRS directly or work with a tax professional to review the calculation. The IRS worksheet for calculating taxable SSDI is in the Form 1040 instructions. If you believe an error was made, you can file an amended return (Form 1040-X) within three years of the original filing date.