Yes, if the gain is a long-term one, it is currently taxed at different rates, depending on your marginal tax bracket. The gain is taxed at 0% if your taxable income falls in the 10% or 15% marginal tax brackets; 15% if your taxable income falls in the 25%, 28%, 33%, or 35% marginal tax brackets; and 20% if your taxable income falls in the 39.6% marginal tax bracket. It is best to consult a tax professional about your liability.