Social Security: How It’s Taxed, How to Save - NerdWallet (2024)

Social Security retirement benefits are subject to federal income tax for most people, though a portion of the benefits are exempt from taxes. People with lower total retirement income get larger exemptions. Most states don’t tax Social Security. Supplemental Security Income (SSI) is not taxable.

Social Security retirement income can be taxable no matter how old you are. Whether your Social Security benefits are subject to income tax depends on your total income, not your age.

Social Security Disability Insurance (SSDI), which is a separate program for people with qualifying disabilities, also may be taxable.

However, Supplemental Security Income (SSI) is not taxable. SSI is a monthly Social Security benefit for people with limited resources, low incomes and who are blind, disabled or 65 or older.

Federal taxes

Two factors determine the percentage of your Social Security that’s taxable:

The percentage of your Social Security retirement benefit that’s “taxable” isn’t equal to the percentage you pay in taxes. For example, if your annual Social Security benefit is $20,000 and 50% is taxable, you won’t lose half to taxes; it means you’ll only pay taxes on $10,000 of your Social Security benefits. Even if 85% of your benefit is taxable — which is the maximum amount — you’re still getting a 15% exemption compared to earned income.

Your actual tax bill is determined by federal income tax rates, which currently range from 10% to 37%. The IRS has a worksheet to help you figure your tax, or you can use tax software. If your annual combined income is low enough, you won’t owe any taxes on your Social Security.

State taxes

Where you live determines whether you also owe state taxes. Most states don’t tax Social Security, and states that do tax it typically exempt a percentage or a dollar amount.

The way Social Security taxes work can cause a sharp rise and then drop in marginal tax rates, sometimes called the “tax torpedo.” (A marginal tax rate is basically how much additional tax you pay on an additional dollar of income.)

Here's why: The income thresholds at which more of your Social Security is taxed are not the same as federal tax brackets. You might have other income, such as Roth IRA withdrawals, that don’t push your total income into higher tax brackets. But going from 0% to 50% of your benefit being taxable (or 50% to 85%) has the effect of boosting your marginal tax rate, even if your federal tax bracket doesn’t change.

Once your income exceeds a certain level and you've paid all the taxes on your benefit you could possibly pay, your marginal tax rate settles back down to equal your federal tax bracket.

Middle-income people can reduce the tax torpedo’s effect by delaying the start of Social Security benefits until age 70 and taking income instead from retirement accounts or other savings, according to researchers William Reichenstein, a professor at Baylor University, and William Meyer, founder and managing principal of Social Security Solutions Inc., who presented their findings in the July 2018 Journal of Financial Planning . The larger benefit at age 70 means people can draw less from their other accounts, resulting in a lower tax bill.

The tax torpedo also affects higher-income people, but there's not much they can do about it once 85% of their benefits are subject to taxation. Instead of worrying about the torpedo, their focus instead should be strategies to reduce the income that determines premiums for Medicare Part B and Part D, the researchers found.

Juggling all this is complicated enough that it can pay to consult a tax pro before you start Social Security or withdrawals from retirement funds.