After-Tax 401(k) Money: Splitting It at Rollover for a Tax-Free Roth

IRS Notice 2014-54 lets you split a 401(k) distribution at separation: your after-tax contributions roll directly to a Roth IRA with no tax due, while the pre-tax money and all earnings roll to a traditional IRA. It applies to after-tax non-Roth contributions and moves money otherwise locked in a tax-deferred account into a Roth without writing a check to the IRS.

What Notice 2014-54 Permits

Before 2014, the IRS position was that any 401(k) distribution had to be allocated proportionally: if 15% of your account was after-tax, then 15% of every dollar you moved was after-tax, wherever it went.

Notice 2014-54 changed that. On a single distribution at separation, you can direct the two components to different destinations: after-tax contributions to a Roth IRA (already taxed, so nothing due) and everything else, including the earnings on those after-tax contributions, to a traditional IRA.

This works as a direct rollover with explicit written instructions to the plan: one distribution, two destinations. The 1099-R the plan issues shows your after-tax amount in Box 5, and that figure is what moves to the Roth.

Rules and Watchouts

• The most common mistake is letting the plan default: most administrators roll the entire balance into one traditional IRA unless you instruct otherwise.
• Earnings on after-tax contributions are pre-tax in character. Only the contributions themselves move to the Roth tax-free.
• After-tax non-Roth money is not the same as Roth 401(k) money, even when a plan shows them together. Roth 401(k) balances roll to a Roth IRA separately, contributions and earnings both tax-free.
• You must be separated from service or otherwise eligible for a distribution. This is not the in-service mega backdoor Roth, which requires plan features many plans lack; the split needs none of that because you are leaving anyway.
• If you do not already have a Roth IRA, the five-year clock for tax-free earnings starts the year the Roth IRA is first opened.

A Worked Example

You leave a job with $400,000 in the plan: $60,000 of after-tax contributions, $18,000 of earnings on them, and $322,000 of pre-tax contributions and earnings. At rollover, you instruct the administrator to send $60,000 to your Roth IRA and $340,000 to your traditional IRA ($18,000 of that being the pre-tax earnings on the after-tax money). No tax is due on the $60,000 because it was already taxed.

How This Connects to the 401(k) Rollover Decision

The split rollover is one maneuver within the broader set of choices you face when leaving an employer, covered in our parent guide: 401(k) Rollover: A Complete Guide to Moving an Old Retirement Account. In the Sporos framework it lives in the Soil layer, the tax architecture of the plan, because Roth dollars acquired at no tax cost compound in your favor for decades.

Frequently Asked Questions

Does my plan have to allow this?

No. Notice 2014-54 is federal guidance that applies to any qualified plan distribution; what the plan does need is a record of your after-tax contribution basis, so ask the administrator or HR for a statement first.

Can I roll after-tax 401(k) money into an existing Roth IRA?

Yes, it goes into whatever Roth IRA you designate. A rollover contribution is not a regular annual contribution, so it does not count against the $7,000 (2024) annual Roth IRA limit.

What if I already rolled everything into a Traditional IRA?

The after-tax basis is not lost; you track it on Form 8606 each year, and it reduces the taxable portion of future distributions or conversions. Less clean than the split rollover, but recoverable.

Is this the same as a backdoor Roth IRA?

No. The backdoor Roth is a non-deductible traditional IRA contribution followed by a conversion; this is a direct split of existing after-tax 401(k) money at separation, the same result in spirit but a different mechanism and scale.

What to Do Next

What decides this for you. Whether your plan tracked after-tax contributions as a separate source. If it did, the distribution can be split so the after-tax money lands in a Roth IRA tax-free and only the earnings on it go to a traditional IRA. If your plan never separated the sources, there is nothing to split.

Where it goes wrong. The split has to be directed at the moment of distribution. It is not something a custodian can unwind afterwards. Once after-tax dollars are commingled inside one traditional IRA, that basis is yours to prove, on a form most people have never filed correctly, and the pro-rata rule then taxes a share of every future conversion you attempt. The mistake is silent: the money moves, the balance looks right, and the cost only appears years later when a backdoor Roth turns out to be mostly taxable.

Worth a conversation if you have after-tax money sitting in a plan, you are separating and the paperwork is in front of you, or you already rolled and are not certain the split was executed. That last one is worth checking before you convert anything. Book a call.

The information provided is for educational purposes only and does not constitute investment, legal, or tax advice. Tax law changes frequently — verify current rules before acting. Consult with qualified professionals for guidance specific to your situation.