Social Security is taxable income, but only if your other income crosses certain thresholds
Whether you owe federal income tax on Social Security depends on your combined income — not just what you receive from Social Security. The IRS uses a formula that includes your adjusted gross income, nontaxable interest, and half of your Social Security benefits. If that total stays below a certain level, you pay no tax on your benefits. If it exceeds that level, you may owe tax on 50% or 85% of what you received.
The thresholds are the same for everyone and do not adjust for inflation year to year. For 2024, the first threshold is $25,000 for single filers and $32,000 for married couples filing jointly. These numbers have not changed since 1984. Because they are fixed while incomes and benefit amounts rise, more people cross them each year.
Key Takeaways
- You calculate tax on Social Security using combined income, which includes half your benefits plus all other income sources.
- If combined income stays below $25,000 (single) or $32,000 (married filing jointly), you owe no federal tax on your benefits.
- Once you cross the first threshold, up to 50% of your benefits become taxable; crossing the second threshold makes up to 85% taxable.
- The IRS thresholds have remained unchanged since 1984, so more retirees are affected each year as incomes rise.
- Your state may also tax Social Security benefits, depending on where you live and your income level.
How the IRS calculates combined income
The IRS calls this figure combined income, and it is the starting point for determining whether your benefits are taxable. To calculate it, add your adjusted gross income (the number at the bottom of page 1 of your Form 1040) plus any nontaxable interest you earned plus half of your Social Security benefits.
Nontaxable interest usually comes from municipal bonds or certain savings bonds. If you have no nontaxable interest, you skip that part. The half of your benefits is a formula amount — you do not actually receive two separate payments from Social Security.
Example: You are single, earned $20,000 from a part-time job, received $18,000 in Social Security, and had $500 in nontaxable interest. Your combined income is $20,000 + $500 + ($18,000 × 0.5) = $29,500. This exceeds the $25,000 threshold, so some of your benefits are taxable.
The two income thresholds and what they mean
The IRS uses two thresholds. Crossing the first one means up to 50% of your benefits become taxable. Crossing the second one means up to 85% become taxable. The thresholds are:
| Filing Status | First Threshold | Second Threshold |
|---|---|---|
| Single | $25,000 | $34,000 |
| Married Filing Jointly | $32,000 | $44,000 |
| Married Filing Separately | $0 | $0 |
If you file married filing separately, the thresholds are effectively zero — meaning any Social Security you receive is likely taxable. This filing status is rarely advantageous for Social Security purposes.
The amount of your benefits that becomes taxable is not a flat percentage. Instead, the IRS uses a formula that depends on how far above the threshold your combined income reaches. The closer you are to the threshold, the less of your benefits are taxed. The further above it you go, the more are taxed, up to the 50% or 85% cap.
What happens when you cross the first threshold
If your combined income exceeds $25,000 (single) or $32,000 (married filing jointly), the IRS taxes the lesser of two amounts: either 50% of your benefits, or 50% of the amount by which your combined income exceeds the threshold.
Using the earlier example where your combined income was $29,500: you exceeded the first threshold by $4,500. Half of that is $2,250. Half of your $18,000 in benefits is $9,000. The lesser amount is $2,250, so $2,250 of your Social Security is taxable. You would report this on your Form 1040 and pay ordinary income tax on it at your marginal rate.
This means that crossing the threshold by a small amount results in only a small portion of your benefits being taxed. The tax does not jump suddenly; it increases gradually as your income rises.
What happens when you cross the second threshold
If your combined income exceeds the second threshold ($34,000 for single filers, $44,000 for married filing jointly), a more complex formula applies. You now owe tax on the greater of two calculations: either the amount from the first threshold formula, or 85% of the amount by which your combined income exceeds the second threshold, plus 50% of your benefits minus 50% of the excess over the first threshold.
In practice, this means that once you cross the second threshold, the percentage of your benefits that are taxable rises toward the 85% cap. The exact percentage depends on how far above the second threshold your combined income reaches. Very few people end up with exactly 85% of their benefits taxed; most fall somewhere between 50% and 85%.
The second threshold exists to prevent people with very high incomes from paying tax on only 50% of their benefits. It ensures that high-income retirees pay tax on a larger share.
State taxes on Social Security
Thirteen states tax Social Security benefits to some degree: Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. The rules vary significantly by state.
Some states use the same federal thresholds; others use different ones. Some tax only the portion that is taxable at the federal level; others tax a different percentage. A few states have begun phasing out their Social Security tax or raising their thresholds. Because these rules change, you should check your state's tax authority website or speak with a tax preparer who knows your state's current rules.
If you live in a state that does not tax Social Security, you still owe federal tax if your combined income exceeds the federal thresholds. The two are separate calculations.
How to report taxable Social Security on your return
Social Security benefits appear on the Form SSA-1099 that you receive each January. This form shows the total benefits you received in the prior year. You use this amount to calculate your combined income and determine whether any portion is taxable.
On your Form 1040, you report your total Social Security in the "Social Security benefits" line. If any portion is taxable, you also complete a worksheet (usually in the Form 1040 instructions) to calculate the taxable amount. You then add that taxable amount to your other income and report it on the appropriate line of your return.
If you use tax software, the program walks you through the calculation once you enter your Social Security amount and other income. If you file by hand or with a preparer, the preparer performs the calculation for you. Either way, the formula is the same.
Frequently Asked Questions
Can I reduce the tax on my Social Security by timing when I claim it?
Claiming at a younger age means lower monthly benefits but potentially lower combined income in early retirement years. Claiming later means higher monthly benefits but higher combined income. The tax impact depends on your other income sources and how long you live. A financial planner or tax preparer can model both scenarios for your situation.
Does the tax on Social Security explore to Supplemental Security Income (SSI)?
No. SSI is a needs-based program for people with low income and assets. It is not taxable income and does not count toward combined income for Social Security tax purposes. Only benefits from the regular Social Security program (OASDI) are subject to this tax.
What if I worked while receiving Social Security before full retirement age?
Earnings from work do count toward your combined income for tax purposes. If you earned wages while receiving benefits, those wages are part of your adjusted gross income and increase the likelihood that your benefits will be taxed. The earnings limit that reduces your benefits is separate from the tax calculation.
Do I have to pay estimated tax on Social Security if some of it is taxable?
You may need to if the tax withheld from your benefits is not enough to cover your total tax liability. You can ask Social Security to withhold more from your monthly payment using Form W-4V, or you can make quarterly estimated tax payments. A tax preparer can tell you whether you need to do either.
If I live abroad, do I still owe U.S. tax on Social Security?
Yes, if you are a U.S. citizen or resident alien, you owe federal tax on taxable Social Security benefits regardless of where you live. Some countries have tax treaties with the United States that may affect this, so consult a tax professional who handles expatriate returns.