SSDI taxation in 2018 followed the same formula as today

In 2018, Social Security Disability Insurance (SSDI) was taxable to some recipients but not others, depending on their total income. The rule was not new in 2018 and has not changed since: if your combined income exceeded a threshold set by law, you owed federal income tax on a portion of your SSDI benefits. The threshold was the same in 2018 as it is now—$25,000 for single filers and $32,000 for married couples filing jointly.

The tax applied only to the amount of SSDI that pushed you over that threshold. You did not pay tax on all your benefits, only on the excess. This meant that many SSDI recipients—those with little or no other income—paid no federal income tax on their benefits at all.

Key Takeaways

  • In 2018, SSDI was taxable only if your combined income (SSDI plus wages, interest, and other sources) exceeded $25,000 for single filers or $32,000 for married couples filing jointly.
  • The tax applied to a portion of your benefits, not all of them—calculated using a formula that depends on how far over the threshold you went.
  • If you had no other income besides SSDI, you owed no federal income tax on your benefits in 2018, and the same rule applies today.
  • State income tax on SSDI varied by state in 2018 and still does; some states taxed SSDI while others did not.

How the 2018 tax calculation worked

The formula for calculating taxable SSDI in 2018 was based on what the IRS called combined income. This meant adding together your SSDI benefits, wages, self-employment income, interest, dividends, and certain other sources. It did not include some income sources—for example, Supplemental Security Income (SSI) was not counted, nor was tax-exempt interest.

Once you had your combined income total, you compared it to the threshold. If you were single and your combined income was $25,000 or less, you owed no federal tax on SSDI. If it was $25,001 to $34,000, you paid tax on up to 50 percent of the excess. If it was above $34,000, you paid tax on up to 85 percent of your benefits.

The reason for the two thresholds was that Congress wanted to protect lower-income recipients while capturing tax from those with substantial other income. A single person with $26,000 in combined income paid tax on only $500 of their SSDI (50 percent of the $1,000 excess). A single person with $50,000 in combined income paid tax on a much larger portion.

Why 2018 had no special SSDI tax rules

2018 was not a year of change for SSDI taxation. The thresholds of $25,000 and $32,000 had been in place since 1983 and have never been adjusted for inflation. This means that over time, more SSDI recipients have crossed the threshold straightforward because wages and other income have risen, even if their SSDI benefit amount stayed the same.

The Tax Cuts and Jobs Act, passed in December 2017, changed federal income tax rates and brackets for 2018, but it did not change the SSDI taxation rules themselves. The thresholds remained frozen at their 1983 levels.

State income tax on SSDI in 2018

While federal tax rules were consistent across the country, state tax treatment of SSDI in 2018 varied widely. Some states—including Illinois, Mississippi, and Pennsylvania—did not tax SSDI at all. Others taxed it under the same rules as the federal government. Still others had their own thresholds and formulas.

If you lived in a state that taxed SSDI in 2018, you would have needed to check your state's specific rules. Your state's tax agency website or a tax preparer familiar with your state's law could tell you whether you owed state tax on your benefits. This variation by state still exists today.

How to know if you owed tax on 2018 SSDI

The Social Security Administration sent you a form SSA-1099 in January 2019 showing how much SSDI you received in 2018. You used this form along with your other income documents to calculate your combined income. If the total exceeded the threshold for your filing status, you likely owed federal tax on a portion of your benefits.

Many people did not realize they owed tax on SSDI until they filed their 2018 return or received a notice from the IRS. If you did not file a return and owed tax, the IRS could have assessed penalties and interest. If you think you should have filed a 2018 return but did not, you can still file it now, though the statute of limitations for most years has passed.

Medicare premiums and SSDI in 2018

In 2018, if you received SSDI and were also enrolled in Medicare Part B, your premium was tied to your income from two years earlier. This was called Income-Related Monthly Adjustment Amounts (IRMAA). Your 2018 Medicare premium was based on your 2016 income, not your 2018 income.

This timing mattered because it meant your 2018 SSDI benefit amount did not affect your 2018 Medicare premium. However, if your 2018 income was unusually high—for example, because you returned to work—your 2020 Medicare premium would reflect that. The IRMAA thresholds in 2018 were different from the SSDI tax thresholds, and they were also different from today's thresholds.

Work incentives and SSDI taxation in 2018

If you were working while receiving SSDI in 2018, your wages counted toward your combined income for tax purposes. This meant that returning to work could push you over the threshold and make your SSDI taxable, even if your SSDI benefit itself was not reduced.

The Social Security Administration offered work incentives in 2018 that reduced your SSDI benefit based on work activity, but these did not eliminate the tax issue. For example, the Student Earned Income Exclusion allowed students to exclude some earned income from the benefit calculation, but the excluded income still counted toward combined income for tax purposes. Understanding this distinction was important for anyone trying to work while on SSDI.

Frequently Asked Questions

Did everyone on SSDI pay taxes on their benefits in 2018?

No. Only recipients whose combined income exceeded $25,000 (single) or $32,000 (married filing jointly) owed federal tax on any portion of their benefits. Many people on SSDI had no other income and therefore owed no tax.

Could I have owed state income tax on SSDI in 2018 even if I owed no federal tax?

Yes, depending on your state. Some states taxed SSDI under different rules than the federal government. You would need to check your state's tax agency website or consult a tax preparer to know your state's specific rules for 2018.

If I did not file a 2018 tax return and owed tax on SSDI, what happens now?

The IRS can assess penalties and interest on unpaid tax, but the statute of limitations for most years has passed. If you believe you owed tax in 2018, you can still file a return, though you should consult a tax professional about your specific situation and any potential liability.

Did the 2018 tax law changes affect how SSDI was taxed?

The Tax Cuts and Jobs Act changed federal income tax rates and brackets for 2018, but it did not change the SSDI taxation thresholds or formula. Those thresholds have remained at $25,000 and $32,000 since 1983.

How did working while on SSDI affect my 2018 taxes?

Wages from work counted toward your combined income for tax purposes, which could make your SSDI taxable even if your benefit was reduced due to work activity. The two calculations—benefit reduction and tax liability—were separate.