Whether you have to pay federal income taxes on Social Security benefits mostly depends on your circumstances.

Karen Connelly of the Internal Revenue Services, says if the benefits are your only income for the year, you probably won't have to pay taxes on them and may not even need to file a tax return. On the other hand, if you had other income besides the benefits, you may have to pay taxes on part or all of your benefits, depending on your total income and other factors.

She says people filing on line with the IRS ''Free File" program can automatically find out whether their benefits are taxable income. Other taxpayers can get the information they need at the IRS website.