You may owe federal income tax on Social Security, depending on your total income

Whether you pay federal income tax on Social Security depends on how much other income you have. The IRS uses a formula called combined income to decide this. If your combined income stays below a certain threshold, you pay no tax on your benefits. If it goes above that threshold, you may owe tax on up to 85 percent of your benefits.

Combined income is not the same as your gross income. It equals your adjusted gross income plus nontaxable interest plus half of your Social Security benefits. This formula means that even people with modest incomes can end up owing tax on benefits, because the threshold amounts have not changed since 1984.

The IRS does not automatically withhold tax from Social Security payments the way it does from paychecks. You have to request withholding yourself, or make quarterly estimated tax payments. Many people discover they owe tax only when they file their return.

Key Takeaways

  • Combined income — not just your Social Security amount — determines whether you owe tax, and combined income includes half your benefits plus other income sources.
  • The income thresholds that trigger taxation are $25,000 for single filers and $32,000 for married filing jointly, and these amounts have not changed since 1984.
  • You can request federal income tax withholding directly from your Social Security payment by completing Form W-4V and submitting it to Social Security.
  • If you do not request withholding and expect to owe tax, you may need to make quarterly estimated tax payments using Form 1040-ES.

How the IRS calculates combined income

The IRS starts with your adjusted gross income (AGI) — the number at the bottom of your 1040 form before you claim the standard or itemized deduction. Then it adds back any nontaxable interest you earned, such as interest from municipal bonds. Finally, it adds half of your Social Security benefits.

This formula catches people who think they are below the threshold. Suppose you are single, retired, and have $20,000 in pension income and $18,000 in Social Security. Your AGI is $20,000. Half your benefits is $9,000. Your combined income is $29,000 — above the $25,000 threshold — even though your actual Social Security is only $18,000.

Other income sources that count toward combined income include wages, self-employment income, interest, dividends, capital gains, rental income, and distributions from IRAs or retirement accounts. Income from a part-time job, a spouse's pension, or a side business all push you closer to the threshold.

The two income thresholds and tax brackets

The IRS uses two thresholds. If your combined income is below the first threshold, you owe no tax on your benefits. If it is above the first threshold but below the second, you may owe tax on up to 50 percent of your benefits. If it exceeds the second threshold, you may owe tax on up to 85 percent of your benefits.

For single filers in 2024, the first threshold is $25,000 and the second is $34,000. For married couples filing jointly, the first threshold is $32,000 and the second is $44,000. For married couples filing separately, the first threshold is $0 — meaning almost all of your benefits are taxable if you file separately.

The actual tax you owe depends on which threshold you cross and by how much. The IRS worksheet on the back of Form 1040 or Form 1040-SR walks you through the calculation. Many tax software programs calculate this automatically when you enter your Social Security income.

How to request federal income tax withholding

If you know you will owe tax on your benefits, you can ask Social Security to withhold federal income tax from your monthly payment. You do this by completing Form W-4V, which Social Security calls the "Voluntary Withholding Request." You can print it from Social Security's website, fill it out, and mail it to your local Social Security office, or submit it in person.

On Form W-4V, you choose a withholding rate: 7 percent, 10 percent, 12 percent, or 22 percent of your monthly benefit. You cannot request a specific dollar amount — only a percentage. If you want to withhold $50 a month but your benefit is $1,500, you would need to request 3.3 percent, which is not one of the options, so you would choose 7 percent (about $105).

Withholding takes effect the month after Social Security receives your form. You can change or stop withholding at any time by submitting a new Form W-4V. If you change your income situation during the year — for example, you start a part-time job — you can adjust your withholding mid-year.

Making quarterly estimated tax payments

If you do not request withholding from Social Security but expect to owe tax, the IRS may require you to make quarterly estimated tax payments. This applies if you have income that is not subject to withholding and you expect to owe $1,000 or more in tax when you file your return.

Quarterly estimated payments are due on April 15, June 15, September 15, and January 15 of the following year. You calculate your expected tax for the year, divide it by four, and send that amount to the IRS using Form 1040-ES. The form includes a worksheet to help you estimate your tax and vouchers to include with each payment.

You can pay estimated taxes by mail, by phone, through the IRS website at IRS.gov, or through the Electronic Federal Tax Payment System (EFTPS). If you underpay, you may owe a penalty when you file your return, even if you ultimately get a refund.

What happens if you do not withhold or pay estimated tax

If you owe tax on your Social Security benefits and do not request withholding or make estimated payments, you will owe the full amount when you file your tax return. The IRS will calculate what you owe based on your combined income and the tax brackets for that year.

If you cannot pay the full amount by the filing important date, you have options. You can request a short-term extension to file (Form 4868), which gives you six months to pay. You can also set up a payment plan with the IRS, either online or by phone. The IRS charges interest and penalties on unpaid tax, so paying as soon as you can reduces what you ultimately owe.

Some people find that they owed tax in previous years but did not know it. If you filed a return and did not report your Social Security income or did not calculate the tax correctly, you can file an amended return using Form 1040-X for any of the past three years. The IRS will recalculate what you owe and send you a bill or refund.

State income tax on Social Security

Federal income tax is separate from state income tax. Some states do not tax Social Security at all. Others tax it the same way the federal government does — using combined income and thresholds. A few states tax Social Security only for high-income retirees or have different rules for federal and state purposes.

If you live in a state with an income tax, check your state's tax agency website or call them to learn the rules for Social Security. Some states allow you to request withholding on a separate state form. Others do not allow withholding at all, which means you may need to make state estimated tax payments separately from federal payments.

Frequently Asked Questions

Can I reduce my combined income to avoid tax on Social Security?

You can lower your combined income by reducing other income sources — for example, by delaying a pension payment or spreading an IRA withdrawal over multiple years. However, the formula includes half your benefits, so you cannot eliminate combined income entirely unless your other income is zero. A tax professional can review your specific situation and suggest strategies.

Do I have to report Social Security on my tax return if I do not owe tax?

If your combined income is below the first threshold for your filing status, you do not owe tax on your benefits. However, you still must report the full amount of Social Security you received on your tax return. The IRS uses this information to verify that you reported it correctly and to cross-check with the Social Security Administration.

What if I worked and received Social Security in the same year?

Wages from work count toward your combined income, which may push you over the threshold and trigger tax on your benefits. Additionally, if you are under full retirement age and still working, Social Security may reduce your monthly benefit by $1 for every $2 you earn above an annual limit. This is separate from income tax and is handled by Social Security, not the IRS.

Does my spouse's Social Security count toward my combined income?

No. Each person's combined income is calculated separately. Your spouse's Social Security benefits and income do not count toward your combined income. However, if you file a joint return, the IRS combines your incomes for tax purposes, so your spouse's other income (wages, pensions, interest) does affect your household tax liability.

Can I change my withholding if my income changes mid-year?

Yes. You can submit a new Form W-4V to Social Security at any time to increase, decrease, or stop withholding. Changes take effect the month after Social Security receives your form. If you expect a major change in income — such as starting a job or selling an investment — updating your withholding mid-year can help you avoid owing a large amount at tax time.