The Mega Backdoor Roth IRA and Other Ways to Maximize a 401(k)

After-tax contributions don't count against the salary deferral limit of $19,000, but they do count toward the annual cap of $56,000. After-tax contributions are what they sound like — it's money that's included into the taxable income after taxes are paid, so the money receives all the other benefits of the 401(k) like tax-deferred investment gains and creditor protections.

With after-tax contributions, clients can put their $19,000 salary deferral into the 401(k), get the $19,000 employer match, and then fill in the $18,000 gap to max out the account at $56,000.

Mega-Roth Opportunity

If the plan allows for in-service distributions of after-tax contributions and tracks after-tax contributions and investment gains in separate accounts from salary deferral and Roth money, there's an opportunity to do annual planning for Roth IRAs.

Clients can convert after-tax contributions from a 401(k) plan into a Roth IRA, without having to pay additional taxes. If a plan allows in-service distributions of after-tax contributions, the money can be rolled over to a Roth IRA each year. However, it's important to note that any investment gains on the after-tax amount would still be distributed pro rata and considered taxable. Earnings on after-tax money only receive tax-deferred treatment in a 401(k); they aren't tax free.

Clients can roll over tens of thousands of dollars a year from a 401(k) to a Roth IRA if the plan is properly set up. They can even set up a plan in such a way so the entire $56,000 limit is after-tax money that's distributed to a Roth IRA each year with minimal tax implications. This strategy is referred to as the Mega Backdoor Roth strategy.

Complexities Upon Distribution of After-Tax Contributions

What happens to after-tax contributions in a 401(k) upon distribution? This is a complex area where you can help clients understand the role of two factors:

1. After-tax contributions are distributed pro-rata (proportional) between tax-deferred gain and the after-tax amounts.
2. Pre-tax money is usually considered for rollover into a new 401(k) or IRA first, leaving the after-tax attributed second. The IRS provided guidance on allocation of after-tax amounts to rollovers in Notice 2014-54.

Best Practices for Rollovers

Help your clients navigate the world of rollovers with after-tax contributions by following best practices. If a client does a full distribution from a 401(k) at retirement or separation of service, they can roll the entire pre-tax amount to a new 401(k) or IRA and separate out the after-tax contributions to roll over into a Roth IRA. The IRS Notice 2014-54 previously mentioned also provides guidance for this scenario.

You can help your clients understand after-tax contributions by envisioning after-tax money in a 401(k) as the best of three worlds. These contributions enter after taxes and give your client tax-deferred money on investment growth, allow them to save more money in their 401(k) while also giving them the opportunity to roll it over into a Roth IRA at a later date.

After-tax contributions build numerous planning options and tax diversification into retirement plans. Before your clients allocate money toward after-tax contributions, it's important they understand what their plan allows and how it fits into their overall retirement and financial planning picture.

Jamie Hopkins is the director of retirement research at Carson Group and a finance professor of practice at Creighton University Heider College of Business. Previously, he was a professor at the American College of Financial Services, where he helped co-create the Retirement Income Certified Professional (RICP) designation.