However, the first option is rarely the best one. If you cash in your 401k retirement plan, the tax consequences can be stunning. Almost all, 401k retirement plan consultants will advise you against it. Among the drawbacks: your employer is required to withhold 20% for federal income taxes, you’ll pay a 10% premature withdrawal penalty, (if you are younger than 59½), and the money will no longer be tax-deferred for your retirement. In addition, since it will be counted as taxable income in the year you receive it, you may find yourself in a much higher tax bracket. On larger balances, it’s common to see a 35-40% loss due to these factors. On the other hand, The tax benefits of rolling over your 401k plan to another tax-qualified plan are many. 401k retirement plan consultants or 401k plan advisors can help you weigh the pros and cons before you make a decision.