Social security benefits are taxable only if the sum of 50% of the benefits received plus all other taxable income (however, interest from tax exempt bonds is included in the calculation) for the year exceeds certain base amounts. The base amounts are $25,000 if the filing status is single, $32,000 if married filing jointly, and $0 if married filing separately. If the sum of the income amounts does not exceed the base amounts for a taxpayer's filing status then none of the benefits are taxable. If the sum of the income amounts exceed the applicable base amount then only a portion of the benefits becomes taxable depending on the level of income. The maximum portion that can be subject to tax is 85%.