There are two types of money in a Roth 401(k). The first is the money that you contribute. Since that was taxed before it was paid into the Roth 401(k)it is returned without taxation. The other portion is the earnings or interest that the account accumulates. Once the Roth 401(k) is more than five years old and you have reached fifty and a half years old, that pool of money is also distributed to you free of any income tax.