Social Security benefits are sometimes taxable. In cases where Social Security benefits are an individual's only source of income for the year, the benefits are generally not taxable. They often are taxable when they are one of several sources of income for the year.
To find out if Social Security benefits are taxable or not, the IRS recommends adding one-half of the benefits received during the year to all other income. If the total exceeds a base amount set for the year, then Social Security is most likely taxable. The base amounts established by the IRS as of 2014 are $25,000 for single people or heads of household and $32,000 for couples filing jointly.