When you change jobs, you need to decide what to do with the money in your 401(k) plan. Should you leave it where it is, or take it with you? Should you roll the money over into an IRA or into your new employer's retirement plan? As you consider your options, keep in mind that one of the greatest advantages of a 401(k) plan is that it allows you to save for retirement on a tax-deferred basis. When changing jobs, it's essential to consider the continued tax-deferral of these retirement funds, and, if possible, to avoid current taxes and penalties that can eat into the amount of money you've saved.