Why did the taxable amount of my Social Security benefits change so much from last year?

Whether or not your Social Security income is taxable depends on your total income for the year,  which includes your Social Security plus any other income. If you have other income that varies from year to year, that could change the amount of your Social Security that's taxable.

The basic formula to determine whether your Social Security benefits are taxable includes half of your Social Security income plus all other sources of income, including any tax-exempt interest. Once this total exceeds the base amount for your filing status, a portion of your Social Security income becomes taxable. The three base amounts are:

• $25,000 for single, Head of Household, and qualifying surviving spouse with a dependent child or married individuals filing separately who didn't live with their spouse at any time during the year.
• $32,000 for married couples filing jointly.
• $0 for married persons filing separately who lived together at any time during the year.

The taxable portion of your Social Security income increases as your taxable income increases and you reach additional thresholds.

Example: If an individual receives $24,000 in Social Security retirement benefits, and also earns $19,000 working a part-time job, their total is $31,000 (half of $24,000, or $12,000, plus $19,000 gives a total of $31,000), which exceeds the base amount for an individual ($25,000). That means a portion of their Social Security is taxable.

The exact amount of your Social Security that's taxable depends on a complicated formula, but all you need to do is enter your income in TurboTax. We'll make the calculations and let you know what, if any, tax you owe on your Social Security benefits.

If your only income comes from Social Security, you most likely won't owe any taxes.