All Social Security Beneficiaries

• According to the Social Security Administration, taxes on social security are capped at 85 percent of your benefits. This means, even if you are required to pay taxes on your social security benefits, the tax will only apply to 85 percent of the benefits you receive. The remaining 15 percent is left untaxed by the federal government. The Social Security Administration also states those who are required to pay taxes on social security benefits usually have other sources of income such as stock dividends, income from self-employment or wages from a job.
  
  

Filing Taxes as Single

• If you are single and file your federal taxes as an individual with an income between $25,000 and $34,000, you are required to pay income tax on up to 50 percent of your social security benefits. If your income exceeds $34,000, you are required to pay income tax on up to 85 percent of your social security benefits. Your obligation to pay income taxes on your benefits can change from year to year as your income fluctuates.
  
  

Filing a Joint Return

• The federal government allows married couples to combine income for the purpose of determining income tax on social security benefits. If you are married and filing a joint return with a combined income between $32,000 and $44,000, you and your spouse are required to pay income tax on up to 50 percent of your social security benefits. If you and your spouse's combined income is greater than $44,000, you are required to pay income tax on up to 85 percent of your social security benefits.
  
  

How Combined Income is Determined

• Your combined income for social security tax purposes isn't just a simple addition of all the money you made over the course of the year. According to the Social Security Administration, your combined income is determined by your gross adjusted income, plus your nontaxable interest, plus half of your social security benefits. This number is then compared to the rules regarding benefit taxation to determine if you owe any income tax on your social security benefits.