The 2018 tax rules for SSDI were the same as they are now

In 2018, the way Social Security Disability Insurance was taxed depended on your total income for that year, not on the amount you received. The IRS used the same formula it uses today: they added up your adjusted gross income, nontaxable interest, and half your SSDI benefit, then compared that sum to a threshold. If you crossed the threshold, part of your benefit became taxable income.

The thresholds in 2018 were $25,000 for single filers and $32,000 for married couples filing jointly. These numbers have not changed since 1984. If your combined income stayed below the threshold, you paid no federal tax on your SSDI that year. If it went above, you owed tax on up to 85 percent of the excess, depending on how far over you went.

Most people receiving SSDI in 2018 did not owe federal tax on their benefits because their total income fell below the threshold. But the rule applied the same way it does now: it was about your whole financial picture, not just the disability check.

Key Takeaways

  • In 2018, SSDI became taxable only if your combined income (wages, interest, half your SSDI benefit) exceeded $25,000 for single filers or $32,000 for married couples filing jointly.
  • The thresholds have remained unchanged since 1984, so the 2018 rules are identical to the current rules.
  • If you stayed below the threshold, you owed no federal income tax on your SSDI that year.
  • Some states taxed SSDI benefits regardless of federal rules, so your state tax liability in 2018 depended on where you lived.

How the 2018 calculation worked step by step

To know whether you owed tax on SSDI in 2018, you had to calculate your "combined income." This was not the same as your adjusted gross income. The IRS added three things together: your adjusted gross income (line 7 on the 1040 form that year), any nontaxable interest you earned, and half of your total SSDI benefit for the year.

Once you had that combined income number, you compared it to the threshold for your filing status. If the number was $25,000 or less (single) or $32,000 or less (married filing jointly), you were done—no tax on the SSDI. If it was higher, you moved to the next step: calculating how much of your benefit was taxable.

The taxable amount was never straightforward arithmetic. The IRS used a two-tier system. The first tier covered the amount by which your combined income exceeded the threshold, up to $9,000 (single) or $12,000 (married). You owed tax on the lesser of that excess or half your SSDI benefit. The second tier applied if your combined income exceeded the first threshold by more than those amounts. In that case, you could owe tax on up to 85 percent of your benefit.

Most people in 2018 never reached the second tier. The calculation was the same whether you filed in 2018 or are looking back at that year now.

Which states taxed SSDI in 2018

Federal tax rules were one thing; state tax rules were another. In 2018, thirteen states taxed SSDI benefits to some degree: Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. Colorado and Utah have since stopped. The rules in each state were different.

Some states taxed SSDI the same way the federal government did—using the combined income threshold. Others taxed it differently or taxed it only if your income exceeded a different threshold. A few states taxed it only if you were over a certain age. If you lived in one of these states in 2018 and received SSDI, you may have owed state tax even if you owed no federal tax, or vice versa.

If you filed taxes in 2018 and lived in one of these states, your state tax return would have asked about SSDI income separately. The instructions for your state form would have shown you how to calculate what was taxable under state law.

How to find your 2018 SSDI benefit amount

To calculate whether you owed tax in 2018, you needed to know the exact amount of SSDI you received that year. Social Security mailed a form called the SSA-1099 to every beneficiary by January 31 of the following year. For 2018 benefits, you would have received the SSA-1099 in January 2019. Box 5 on that form showed your total SSDI benefit for 2018.

If you no longer have that form, you can request a replacement from Social Security. You can call 1-800-772-1213 or visit your local Social Security office. You can also create an account on ssa.gov and view your benefit history online, though the online record shows what you received each month rather than the annual total on one line.

If you filed taxes in 2018 and included SSDI income, the amount you reported should match box 5 of your SSA-1099. If you are reviewing old tax returns or amending a return from that year, that form is the source document the IRS expects to see.

What changed between 2018 and now

The federal tax thresholds for SSDI have not changed since 2018. They remain $25,000 for single filers and $32,000 for married couples filing jointly. The formula for calculating taxable benefits is also the same. If you are looking at 2018 to understand how SSDI taxation works today, the rules are identical.

The main change since 2018 is which states tax SSDI. Colorado and Utah stopped taxing SSDI benefits after 2018, so if you lived in either of those states and received SSDI in 2018, you may have owed state tax that year but would not now. No other state has changed its SSDI tax status since then.

If you are amending a 2018 return or disputing a tax bill from that year, the rules you follow are the same ones in effect today. The IRS has not revised the SSDI tax calculation since 1984.

If you did not file taxes on SSDI in 2018

If you received SSDI in 2018 but did not file a federal tax return that year, whether you should have depends on whether your combined income exceeded the threshold. Many people who receive SSDI have no other income and fall well below $25,000 or $32,000, so they had no filing requirement.

However, if you had other income—from work, pensions, interest, or other sources—your combined income might have exceeded the threshold even if your SSDI alone was below it. In that case, you should have filed a return and reported the taxable portion of your SSDI.

If you believe you should have filed in 2018 but did not, you can still file an amended return. The IRS generally allows you to go back three years to claim a refund, so a 2018 return filed now would still be within that window. A tax professional or your local IRS office can help you determine whether you owe tax on 2018 SSDI and whether filing now would result in a refund.

Frequently Asked Questions

Did everyone who got SSDI in 2018 have to pay taxes on it?

No. Most people receiving SSDI in 2018 did not owe federal tax on their benefits because their combined income fell below the threshold of $25,000 (single) or $32,000 (married filing jointly). You only owed tax if your combined income—which included half your SSDI benefit plus other income—exceeded that threshold.

What if I lived in Colorado or Utah and got SSDI in 2018?

In 2018, both Colorado and Utah taxed SSDI benefits under state law, even though the federal government may not have. You may have owed state tax on your 2018 SSDI even if you owed no federal tax. Both states have since stopped taxing SSDI, but the 2018 tax year followed their old rules.

How do I know if I reported the right amount of SSDI on my 2018 taxes?

Compare the amount you reported to box 5 of your SSA-1099 from January 2019. That form shows your total SSDI for 2018. If the numbers do not match, you may need to file an amended return. Contact the IRS or a tax professional if you are unsure whether the amount you reported was correct.

Can I amend my 2018 tax return now if I think I made a mistake?

Yes. You can file an amended return for 2018 using Form 1040-X. The IRS generally allows three years to claim a refund, so you can still amend a 2018 return. If you owe additional tax, there may be penalties and interest, but filing now is better than not filing at all.