A Roth 401(k) allows after-tax contributions with tax-free qualified withdrawals, combining features of traditional 401(k)s and Roth IRAs. It has no income limits and a 2026 contribution limit of $24,500 across both traditional and Roth accounts. Starting in 2024, Roth 401(k)s have no required minimum distributions during the owner's lifetime. Withdrawals are tax-free if the account is at least five years old and the owner is 59½ or older.