Most Americans have most of their retirement savings in a 401(k) plan or similar employer-sponsored retirement account, which is great. Your contributions to a 401(k) plan can decrease your taxable income today. However, eventually, when you take distributions from the account, you're going to owe ordinary income taxes.
CNBC’s recent article, “A Roth 401(k) offers tax advantages. Here's how it works” says that more employers are offering another option for your retirement savings—a Roth 401(k). When you contribute to a Roth 401(k), the contribution won't lower your taxable income today. However, when you withdraw money in the future, like a Roth IRA, it's tax-free. A Roth 401(k) lets you save much more than a Roth IRA. You can only contribute $6,000 to a Roth IRA, and if you're age 50 or older, you can make an additional catch-up contribution of $1,000.
401(k) plans are more liberal with what you can save. The limit is $19,000 a year to a 401(k) in 2019, and Roth 401(k) plans share that limit. If you are over age 50, you can save an additional $6,000. However, the amount you earn also makes a difference. Roth IRAs have an income cap. You can't contribute to a Roth IRA, if you earn more than $203,000.
The biggest negative with a Roth 401(k) is how contributions might affect your tax liabilities today. If you earn $100,000 a year and save $19,000 to a traditional 401(k), your taxable income would be only $81,000. However, by contrast, if you make the same $19,000 contribution to a Roth 401(k), you'll still have taxable income of $100,000.
There are no tax consequences when you take money out of a Roth 401(k), when you're 59½ and you meet the five-year rule. However, if you take a similar distribution from a traditional 401(k) plan, the money you withdraw is subject to ordinary income tax.
There are also required minimum distributions (RMDs). Roth 401(k) account owners have to take the RMD at age 70½. This is not for Roth IRA owners. Therefore, you may want to roll your Roth 401(k) account over to a Roth IRA account before you turn 70½.
Reference: CNBC (April 23, 2019) “A Roth 401(k) offers tax advantages. Here's how it works”