Internal Revenue Service United States Department of the Treasury
Level Basic Advanced Military International

Income — Social Security Benefits; Form 1040, Line 20a

Finding the Taxable Portion

When Are Benefits Taxable?

Part of the following benefits received by the taxpayer may be taxable:

  • Social security benefits
  • Railroad retirement benefits, tier 1 (social security equivalent portion)

The amount from box 5 of Form SSA-1099 or Form RRB-1099 is used to calculate the taxable portion of the benefits. The taxable amount, if any, of a taxpayer's social security (or social security equivalent) benefits depends upon:

  • Filing status and other reportable income
  • Whether the benefits were the taxpayer's only source of income
    • If the benefits were the only source of income, the taxpayer generally does not need to file a federal income tax return

A portion of the benefits is taxable if total income (including tax-exempt interest) plus one-half of the benefits received is more than certain base income amounts, which vary based upon filing status. A portion of the benefits is also taxable if the taxpayers are filing Married Filing Separately and lived with their spouse at any time during the year.

If the taxpayer received social security benefits and other income, complete the Social Security Benefits Worksheet to calculate the taxable portion.

More Information

The taxable portion of social security benefits is never more than 85% of the net benefits the taxpayer received. In many cases, the taxable portion is less than 50%.

Social Security Benefits Worksheet, line for entering total amount from box 5 of all Forms SAA-1099 and Forms RRB-1099
Social Security Benefits Worksheet

Social Security Benefits Worksheet