The IRS uses what's called "provisional income" to determine how much of your Social Security benefits are taxable. Your provisional income is calculated using the following formula: Provisional income = Adjusted gross income (AGI) + tax-exempt interest + 50% of your Social Security benefits

The GOP should triple the income level which seniors have to meet before their Social Security benefits are taxed.

Tax season usually brings a refund check for most workers, but if you're retired, you could wind up owing the IRS.