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

You may owe federal income tax on your Social Security benefits if your total income exceeds a certain threshold. The IRS calls this threshold your "combined income," and it includes your wages, interest, dividends, and half of your Social Security benefits added together. If your combined income stays below the threshold for your filing status, you pay no tax on your benefits. If it goes above, a portion of your benefits becomes taxable.

The thresholds have not changed since 1984. For a single filer, the first threshold is $25,000; for married filing jointly, it is $32,000. A second, higher threshold exists at $34,000 for single filers and $44,000 for married filing jointly. How much of your benefits you owe tax on depends on which threshold you cross and by how much.

State and local taxes are a separate question. Most states do not tax Social Security benefits at all. A handful of states — including Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, Rhode Island, and Utah — tax benefits under certain conditions, usually based on income level or military service history. Check your state's tax authority website to learn your state's rules.

Key Takeaways

  • You owe federal tax on Social Security only if your combined income (wages, interest, half your benefits) exceeds $25,000 for single filers or $32,000 for married filing jointly.
  • If you cross the first threshold, up to 50 percent of your benefits may be taxable; if you cross the second threshold, up to 85 percent may be taxable.
  • Most states do not tax Social Security, but nine states tax benefits under certain income or service conditions.
  • The IRS provides a worksheet in Publication 915 to calculate exactly how much of your benefits is taxable.

How the IRS calculates your combined income

Combined income is not the same as adjusted gross income (AGI). To find your combined income, start with your AGI, add back certain deductions (such as student loan interest or IRA contributions), and then add half of your Social Security benefits. That total is what the IRS uses to determine whether you owe tax on your benefits.

For example, if you earned $20,000 in wages, received $15,000 in Social Security, and had $2,000 in interest income, your combined income would be $20,000 + $2,000 + (half of $15,000) = $29,500. Since $29,500 exceeds the $25,000 threshold for single filers, some of your benefits would be taxable.

The calculation matters because even a small amount of other income can push you over a threshold. Withdrawals from a traditional IRA, a pension, or a 401(k) count toward combined income. So do wages from part-time work, rental income, and capital gains. Tax-exempt interest from municipal bonds also counts, even though it is not taxable itself.

The two-tier system: how much of your benefits becomes taxable

The IRS uses two tiers to determine the taxable portion of your benefits. If your combined income exceeds the first threshold but not the second, up to 50 percent of your benefits may be taxable. If your combined income exceeds the second threshold, up to 85 percent of your benefits may be taxable.

The exact amount depends on how far above the threshold you are. The IRS provides a detailed worksheet in Publication 915 to calculate this. The worksheet is complex, but it follows a step-by-step formula that accounts for both tiers. Many people use tax software or work with a tax preparer to complete it accurately.

In practice, very few people owe tax on more than 85 percent of their benefits. The 85 percent cap means that even if your combined income is very high, the maximum taxable portion of your benefits is capped at 85 percent.

Withholding and estimated tax payments

If you owe tax on your Social Security benefits, you have two ways to pay: withhold from your benefits or make estimated tax payments. The Social Security Administration allows you to request that a percentage of your monthly benefit be withheld for federal income tax. You can choose to withhold 7, 10, 15, or 22 percent of your benefit.

To set up withholding, complete Form W-4V and submit it to your local Social Security office or mail it to the address on the form. You can change your withholding request at any time, and you can stop withholding if your situation changes.

Alternatively, if you have other income and expect to owe tax, you can make quarterly estimated tax payments using Form 1040-ES. This approach works well if your tax bill comes mostly from wages or investment income rather than benefits.

State tax treatment of Social Security benefits

Nine states currently tax Social Security benefits under certain conditions. Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, Rhode Island, and Utah each have their own rules about who must pay state tax on benefits.

Some of these states exempt benefits entirely for taxpayers below a certain income level. Others tax benefits the same way the federal government does, using combined income thresholds. A few states offer exemptions for military service or other factors. Because the rules vary widely, you should check your state's tax authority website or contact them directly to learn whether your benefits are taxable in your state.

If you live in one of these nine states and move to a state that does not tax benefits, you may owe back taxes to your former state for the years you lived there. The reverse is also true: if you move to a state that taxes benefits, you may owe tax on benefits you received while living elsewhere, depending on state law.

Using IRS Publication 915 to calculate your tax

Publication 915, "Social Security and Equivalent Railroad Retirement Benefits," is the official IRS guide to determining how much of your benefits is taxable. It contains a worksheet that walks you through the calculation step by step. The worksheet accounts for both income tiers and produces a final number: the amount of your benefits subject to federal income tax.

You can read Publication 915 free from the IRS website (irs.gov). The publication also explains special rules for people who received benefits for only part of the year, those who are married filing separately, and those with non-resident alien spouses.

If the worksheet seems overwhelming, tax software such as TurboTax, H&R Block, or TaxAct can calculate this for you. Many tax preparers also handle this calculation as part of their standard service. The cost of professional help is often worth it if your situation is complex or if you want to be certain the calculation is correct.

Frequently Asked Questions

Can I reduce the amount of my benefits that are taxable?

You cannot reduce the portion of your benefits that is taxable, but you can reduce your other income. For example, delaying withdrawals from a traditional IRA, timing capital gains sales, or managing when you take a pension payment can lower your combined income and reduce or eliminate tax on your benefits. A tax preparer or financial advisor can help you plan this.

What if I did not withhold enough tax and owe money when I file?

You can adjust your withholding going forward by submitting a new Form W-4V to Social Security. You can also make estimated tax payments for the current year. If you owe a large amount, the IRS may allow you to set up a payment plan. Contact the IRS directly or work with a tax professional to discuss your options.

Do I have to file a tax return if I only receive Social Security?

If Social Security is your only income and it is below the filing threshold for your age and filing status, you do not have to file. However, filing may be worth it if you had taxes withheld from your benefits, because you could receive a refund. The IRS website has a tool to help you determine whether you must file.

Are my spouse's Social Security benefits taxed separately from mine?

Yes. Each spouse's benefits are treated separately for tax purposes. However, when you file jointly, the IRS combines your income to determine whether either of you owes tax. This can result in a higher combined income threshold being crossed than if you filed separately, though filing separately is rarely advantageous for Social Security recipients.

What is the difference between federal and state tax on Social Security?

Federal tax is determined by the IRS using the combined income thresholds described above. State tax, if your state imposes it, uses rules set by your state and may have different thresholds or exemptions. You must calculate both separately and report them on your federal and state tax returns.