Some people get taxed on their Social Security
Social Security benefits can be subject to income tax if your countable income exceeds certain levels. To figure out if you might owe tax, take half your Social Security benefits for the year and add it to your other taxable income.
If the total exceeds $25,000 for single filers or $32,000 for joint filers, then you’ll possibly have to include a portion of your benefits as taxable income. The exact amount depends on multiple factors, but in some cases, up to 85% of what you receive from Social Security could end up in your taxable income.