Social Security benefits are taxable income in some cases, but not all

Whether you owe federal income tax on your Social Security benefits depends on your total income for the year. The IRS uses a formula based on what they call combined income — your adjusted gross income, plus nontaxable interest, plus half your Social Security benefits. If that number exceeds a certain threshold, a portion of your benefits becomes taxable.

The thresholds are $25,000 for single filers and $32,000 for married couples filing jointly. These numbers have not changed since 1984, so they affect more people now than they did when they were set. If your combined income falls below the threshold, you owe no federal tax on your benefits. If it exceeds the threshold, you may owe tax on up to 85 percent of your benefits, depending on how far over you go.

State tax treatment varies widely. Some states do not tax Social Security at all. Others tax it the same way the federal government does. A few tax it only if your income exceeds a higher threshold. You will need to check your state's rules separately.

Key Takeaways

  • You owe federal tax on Social Security only if your combined income (adjusted gross income plus half your benefits) exceeds $25,000 for single filers or $32,000 for married couples filing jointly.
  • Combined income is calculated by adding your adjusted gross income, any nontaxable interest, and half of your Social Security benefits for the year.
  • If you exceed the threshold, between 50 and 85 percent of your benefits may be taxable, depending on how much your combined income exceeds it.
  • State tax rules for Social Security vary — some states tax it, some do not, and some use different thresholds than the federal government.
  • The IRS sends Form SSA-1099 each January showing the benefits you received, which you use to calculate your tax liability.

How the IRS calculates combined income

The IRS starts with your adjusted gross income (AGI) — the number at the bottom of page 1 of your tax return. Then it adds back certain deductions that reduce AGI, including tax-exempt interest from municipal bonds and the deduction for student loan interest. Then it adds half of the Social Security benefits you received during the year.

This combined income figure is what determines whether any of your benefits are taxable. It is not the same as your total income, and it is not the same as your AGI. The formula exists because Congress wanted to tax benefits only for people with substantial other income, not for people whose only income is Social Security.

If you are married and file jointly, you combine your spouse's income with yours. If you are married and file separately, the threshold drops to zero — meaning you will almost certainly owe tax on at least some of your benefits if you received any.

The two-tier tax structure for benefits

The tax code creates two separate tiers. In the first tier, if your combined income exceeds the threshold by up to $9,000 (for single filers) or $12,000 (for married couples filing jointly), up to 50 percent of your benefits become taxable. In the second tier, if your combined income exceeds the threshold by more than those amounts, up to 85 percent of your benefits become taxable.

The actual percentage depends on the specific numbers. The IRS worksheet in the instructions to Form 1040 walks through the calculation, but the result is never more than 85 percent of your benefits, even if your combined income is very high. This means that even high-income retirees keep at least 15 percent of their benefits tax-free.

For example, a single filer with combined income of $30,000 (which is $5,000 over the $25,000 threshold) would have up to 50 percent of benefits taxable. A single filer with combined income of $35,000 (which is $10,000 over the threshold) would have up to 85 percent of benefits taxable.

What counts as income for this calculation

Wages, self-employment income, pensions, and distributions from retirement accounts all count toward combined income. Interest and dividends count. Capital gains count. Rental income counts. Distributions from IRAs and 401(k)s count, whether or not you needed to take them.

Some types of income do not count. Supplemental Security Income (SSI) does not count. Veterans benefits do not count. Workers' compensation does not count. However, nontaxable interest from municipal bonds does count for this purpose, even though it does not count as income on your tax return.

If you are still working while receiving Social Security, your wages count in full. There is no separate earnings test for tax purposes — the earnings test that reduces your benefits before full retirement age is separate from the tax calculation.

How to report Social Security on your tax return

In January, the Social Security Administration sends you Form SSA-1099 showing the total benefits you received in the previous year. You use this number to calculate your combined income. If you determine that some of your benefits are taxable, you report the taxable amount on line 5b of Form 1040 (or the equivalent line on your state return).

You do not report the full amount of benefits received — only the taxable portion. The IRS worksheet in the Form 1040 instructions helps you calculate this. If you use tax software, it will do the calculation for you once you enter the total benefits from your SSA-1099.

If you expect to 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 and submitting it to Social Security. Withholding can help you avoid owing a large amount when you file your return.

State tax treatment of Social Security benefits

Thirteen states do not tax Social Security benefits at all: Alaska, Florida, Illinois, Iowa, Kansas, Louisiana, Maine, Mississippi, Missouri, Nevada, New Hampshire, South Dakota, Tennessee, and Wyoming. If you live in one of these states, you owe no state income tax on your benefits regardless of your income.

Most other states follow the federal rule — if your benefits are taxable under federal law, they are taxable under state law. A few states use different thresholds or different calculations. Colorado, for example, exempts Social Security from state tax for most retirees but taxes it for high-income filers. Connecticut taxes it only if your income exceeds $75,000 for single filers.

Check your state's tax agency website or your state tax return instructions to learn the specific rule where you live. State rules change occasionally, so it is worth confirming each year.

Planning to reduce taxes on benefits

If you are close to the income threshold, you may be able to reduce the amount of your benefits that are taxable by managing your other income. Delaying a large distribution from a retirement account, timing the sale of an investment, or deferring self-employment income to the next year can all lower your combined income in a given year.

Roth conversions — moving money from a traditional IRA to a Roth IRA — increase your income in the year of the conversion, which can push more of your Social Security benefits into the taxable range. This is a trade-off worth considering with a tax professional if you are doing large conversions.

If you are still working, earning wages does not trigger any special tax treatment of your benefits — it counts as regular income. However, if you have not yet reached full retirement age and you earn above a certain amount, Social Security will reduce your monthly benefit payment. This earnings test is separate from the tax calculation.

Frequently Asked Questions

Can I avoid paying tax on Social Security by not reporting it?

No. Social Security is reported to the IRS by the Social Security Administration on Form SSA-1099, so the IRS knows what you received. If you owe tax on your benefits and do not report it, you risk penalties and interest on the unpaid amount.

What if I received benefits for only part of the year?

You report only the benefits you actually received. If you started receiving benefits in June, for example, your SSA-1099 will show only the six months of payments. You use that actual amount in the combined income calculation.

Does the standard deduction reduce my combined income?

No. Combined income is calculated before the standard deduction. The standard deduction reduces your taxable income after you determine how much of your benefits are taxable. This is why someone with low total income might owe no tax even if some benefits are technically taxable.

If I am married filing separately, do I have to pay tax on my benefits?

Almost certainly yes. The threshold for married filing separately is zero, meaning that if you received any Social Security and file separately from your spouse, you will owe tax on at least some of your benefits unless your combined income is also zero.

What happens if I owe tax but did not have withholding?

You report the tax owed on your return and pay it with your return, or you can make estimated tax payments throughout the year. If you expect to owe more than $1,000, the IRS may charge a penalty for underpayment of estimated tax, though exceptions exist for people over 65 and those with low income.