Your income is your income, and it will be taxed at your tax rate. The employer may withhold a little more from a bonus or lump sum when they pay you, but you are not ultimately going to be taxed more. You will enter the amounts from your W-2 and the software will calculate your refund or tax due at the correct tax rate for the total amount of income you received.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**