Whether you pay tax on Social Security depends on your other income

Not all Social Security income is taxed, and for many people, none of it is. The amount you owe in federal income tax on your benefits depends on your combined income — that is, your adjusted gross income plus non-taxable interest plus half your Social Security benefits. If that combined income stays below a certain threshold, you owe nothing on your benefits. If it goes above the threshold, between 50 and 85 percent of your benefits become taxable.

The thresholds are the same whether you file single or married filing jointly, but they have not changed since 1984. That means more people cross them each year as wages and benefits rise. State income tax is separate: thirteen states tax Social Security income, and the rules vary by state.

Key Takeaways

  • You owe federal tax on Social Security only if your combined income exceeds $25,000 (single) or $32,000 (married filing jointly).
  • Combined income means your adjusted gross income plus half your Social Security benefits plus any non-taxable interest.
  • If you cross the threshold, between 50 and 85 percent of your benefits become taxable, depending on how far above the threshold you go.
  • Thirteen states tax Social Security income under their own rules, separate from federal tax.
  • The IRS does not automatically withhold tax from your benefits, so you may need to make quarterly estimated payments or request withholding.

The two income thresholds that determine your tax bill

The IRS uses two thresholds to calculate how much of your Social Security is taxable. The first threshold is $25,000 for single filers and $32,000 for married couples filing jointly. If your combined income is at or below that number, you owe no federal tax on your benefits.

The second threshold is $34,000 for single filers and $44,000 for married couples filing jointly. If your combined income falls between the first and second threshold, up to 50 percent of your benefits become taxable. If your combined income exceeds the second threshold, up to 85 percent of your benefits become taxable.

These thresholds have remained unchanged since 1984, which means they have not kept pace with inflation. A person earning $30,000 in other income in 1984 was solidly middle-class; today that same income is much lower in real terms, but the threshold is the same. As a result, more beneficiaries pay tax on their benefits now than in the past.

How to calculate your combined income

Combined income is not the same as your adjusted gross income (AGI). To find your combined income, start with your AGI from your tax return, then add back certain deductions and add half your Social Security benefits.

Specifically, combined income equals your AGI plus any tax-exempt interest (such as interest from municipal bonds) plus half your Social Security benefits. If you have no tax-exempt interest and no other adjustments, you can use your AGI as a starting point and add half your benefits.

The Social Security Administration sends you a Form SSA-1099 each January showing the total benefits you received in the previous year. Divide that number by two and add it to your other income. If the result exceeds the first threshold, you will owe tax on at least some of your benefits.

What percentage of your benefits becomes taxable

The calculation is tiered. If your combined income is between the first and second threshold, you take the amount over the first threshold, multiply it by 50 percent, and that is the amount of benefits subject to tax — up to a maximum of 50 percent of your total benefits.

If your combined income exceeds the second threshold, the calculation is more complex. You add 85 percent of the amount over the second threshold to 50 percent of the amount between the first and second threshold. The result is the amount of your benefits subject to tax, up to a maximum of 85 percent of your total benefits.

For example, a single filer with combined income of $30,000 and $20,000 in Social Security benefits would have $5,000 over the first threshold ($30,000 minus $25,000). Half of that is $2,500, so $2,500 of the $20,000 in benefits becomes taxable. A single filer with combined income of $40,000 and the same $20,000 in benefits would owe tax on a larger portion because the income exceeds the second threshold.

State income tax on Social Security

Thirteen states tax Social Security income: Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. Each state uses its own rules, and some offer partial exemptions based on age or income.

Colorado, Kansas, and Missouri exempt all Social Security income from state tax. Connecticut, Minnesota, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia tax it but often with income thresholds or exemptions for people over a certain age. Check your state's tax authority website or speak with a tax preparer who knows your state's rules.

How to handle tax withholding on your benefits

The IRS does not automatically withhold federal income tax from your Social Security payments. If you expect to owe tax on your benefits, you have two options: request voluntary withholding from your benefits, or make quarterly estimated tax payments.

To request withholding, fill out Form W-4V and send it to your local Social Security office. You can choose to have 7, 10, 12, or 22 percent of your monthly benefit withheld. This is simpler than estimated payments but gives you less control over the exact amount.

If you have other income sources and want more precision, you can make quarterly estimated tax payments directly to the IRS using Form 1040-ES. This route requires you to predict your income for the year and pay in four installments, but it lets you adjust the amount based on your actual situation.

What happens if you do not pay tax on taxable benefits

If you owe tax on your Social Security benefits and do not pay it, the IRS will treat it like any other unpaid tax. You may face penalties, interest, and collection action. The IRS can also reduce future tax refunds to cover the debt.

If you realize you owe tax for a prior year, you can file an amended return using Form 1040-X. The sooner you file, the smaller the interest and penalties will be. If you cannot pay the full amount, the IRS offers payment plans and other relief options.

Frequently Asked Questions

Do I have to pay tax on all my Social Security benefits?

No. If your combined income is below $25,000 (single) or $32,000 (married filing jointly), you owe no federal tax on your benefits. Even if you are above those thresholds, only 50 to 85 percent of your benefits become taxable, never 100 percent.

Does working part-time increase the tax on my Social Security?

Yes, because wages count toward your combined income. Even a small amount of work income can push you over a threshold and make some of your benefits taxable. The same is true for pension income, investment income, and rental income.

Can I reduce the tax on my benefits by taking a Roth conversion?

No. A Roth conversion increases your combined income in the year you do it, which can make more of your benefits taxable that year. However, it does not reduce your tax burden on benefits in future years.

What if I moved to a state that does not tax Social Security?

You would no longer owe state income tax on your benefits in that state, but you would still owe federal tax if your combined income exceeds the federal thresholds. State tax rules do not change your federal tax liability.

How do I know if I should request withholding or make estimated payments?

Request withholding if your only income is Social Security and a small amount of other income, and you want a straightforward solution. Use estimated payments if you have multiple income sources and want to fine-tune the amount withheld each quarter.