 Well, in some cases, you may be able to roll over your 401k without tax withholdings. Let's use a couple of examples. Let's say you take the money out of your 401k when you change jobs and they pay it to you, if you would. In this scenario, they're going to withhold 20% of the taxes to cover the income tax. Then if you don't quickly put the entire distribution, including the 20% in a different retirement account, you're going to be slapped with income taxes immediately.