When Roth 401(k) contributions are distributed, you do not have to include this money in your taxable income because you already paid taxes in the year you made the contribution. Two requirements must be met for a Roth distribution to be qualified: You must have had a Roth 401(k) account for at least five years, and you are age 59½, become disabled, or have died.
If a distribution from a Roth 401(k) is not qualified, the earnings portion of the distribution (but not the Roth contributions) will be taxable. The earning may also be subject to a 10% early distribution tax if you are younger than age 59½ unless a penalty exception applies.