Roth 401(k)s are now permitted for nearly 90% of retirement plans. If your employer is among them, you may be wondering how a Roth 401(k) differs from a Roth IRA. In 2022, you can stash away up to $20,500 in a Roth 401(k)—$27,000 if you’re age 50 or older. Roth IRA contributions, by comparison, are capped at $6,000—$7,000 if you’re 50 or older.