Post-Tax 401-K Contributions

You don't report anything. The plan keeps an account, and you want to follow your statements there to make sure everything is properly recorded.

If you ever roll the after-tax 401(k) contributions into a traditional IRA you'll report that on Form 8606.

Phil> You don't report anything. The plan keeps an account, and you want to Phil> follow your statements there to make sure everything is properly recorded.

Phil> If you ever roll the after-tax 401(k) contributions into a Phil> traditional IRA you'll report that on Form 8606.

Is there any way to roll the after-tax portion of a 401(k) into one IRA account, and the pre-tax portion into another IRA account? That would at least make *my* recordkeeping easier, when the time comes.... (Likewise for Roth 401(k) funds.)

Roth 401(k)'s can be rolled into only Roth IRAs, and all contributions in both are after-tax, so I don't understand that part of the question.

You can direct transfers from your 401(k) to traditional IRAs any way the plan will go along with. Your tax returns will look exactly the same when the rollover happens and when you begin withdrawals if you roll everything from the 401(k) into the traditional IRAs, regardless of how you split it up.

You do have some different distribution (not rollover) options when there are after-tax 401(k) contributions. See IRS Publication 575.

Phil> Roth 401(k)'s can be rolled into only Roth IRAs, and all contributions in Phil> both are after-tax, so I don't understand that part of the question.

Ah, let me explain a bit more. My employer's plan as of 2008 has a roth option, so my account now has pre-tax funds (my contributions and company match), after-tax funds (my contributions), and roth funds (my contributions).

Whenever the time comes to roll out contents, it sounds like at least the Roth portion gets treated separately from the taxable/non-taxable sections, although the custodian mostly just lumps it all together for total valuation right now.

Let's hope there are also some earnings.

Since the Roth 401(k) option only began for you this year it may be too soon for you to have seen exactly how the statements will look. What you need to keep an eye out for is to make sure that the following items are distinguishable:

1. Roth contributions
2. Roth earnings
3. After-tax "traditional" contributions
4. Everything else

Those four totals are all you'll need to know when it comes time to move money out of the 401(k). (For the sake of simplicity I'm ignoring company stock. If you have company stock in your 401(k) there's more accounting.)