Roth 401(k) contributions are included in your taxable income in the year they are made. When you disburse your Roth 401(k) funds, which include your contributions plus any earnings that have accumulated over time, the distribution will be tax-free so long as your distribution is qualified.
A qualified distribution is one that is made at least five years after your first contribution, and after age 59 ½, upon death or disability. If your distribution is non-qualified and if under age 59 1/2, you will pay taxes and a 10% early withdrawal penalty on your earnings only. Learn more about what 401(k) contribution types may be best for you.