The mega backdoor Roth solo 401k strategy is available in self-directed solo 401k plans which are 401k plans for the self-employed with no full-time non-owner W-2 employees. While this strategy is not available in solo 401k plans offered by the banks such as Chase or Wells Fargo or for solo 401k plans offered by the big brokerage firms such as Fidelity Investments, Vanguard or Charles Schwab, for example, a self-directed solo 401k provider such as our company (My Solo 401k Financial LLC) does offer the backdoor Roth solo 401k strategy.
What is a mega backdoor Roth solo 401k?
While not a different kind of solo 401k, a “mega backdoor” Roth solo 401k is is used to move money into the Roth portion of the solo 401k (aka the designated Roth solo 401k), which is done by making nondeductible/voluntary after-tax contributions solo 401k contribution and then converting those funds into the Roth solo 401k or even to a Roth IRA. Voluntary after-tax solo 401k contributions are different from a Roth solo 401k conversion, which is the transfer of tax-deductible contributions in the pre tax solo 401k to the Roth solo 401k. The conversion of pre tax solo 401k to the solo 401k is fully taxable to you in the year of conversion, a mega backdoor Roth solo 401k conversion is not since the contributions were not tax deductible on your personal or business tax return.
Individuals who anticipate being in high tax bracket at retirement or don’t want to be subject to mandatory distributions from their solo 401k, use the mega backdoor Roth solo 401k strategy as a way to combat future tax hikes as one ce your money is in the Roth solo 401k account it can grow tax-free, and qualified distributions from Roth solo 401k plan and Roth IRAs are also tax-free. Another good thing about Roth solo 401k funds is that, unlike with pre tax solo 401k funds, you don’t have to take required minimum distributions.
How the mega backdoor Roth solo 401k strategy works
If you work with a self-directed solo 401k plan provider like My Solo 401k Financial, the mega backdoor Roth solo 401k strategy is pretty straight forward. First open a new solo 401k or restate an existing solo 401k from Fidelity Investments, Charles Schwab, Etrade, or Vanguard, for example to a self-directed solo 401k that allows for voluntary after-tax contributions as well as Roth conversions. As long as you are self-employed with no full-time W-2 employees and generate enough self-employment income to contribute you can maximise your annual voluntary after-tax solo 401k contribution up to the overall yearly limitn which is $69,000 for 2024. The solo 401k plan provider will then assist you in opening the applicable holding accounts and subsequently processing the required Form 1099-R to report the non-taxable mega backdoor Roth solo 401k conversion.
Mega Backdoor Roth Solo 401k taxes
Just the funds in the voluntary after-tax solo 401k are required to be aggregated when processing the Mega Backdoor Roth Solo 401k. This is different then a backdoor Roth IRA where it can get complicated when determining what amount is taxable especially if you have multiple IRAs and IRAs other than IRAs with just nondeductible funds. These complexities are for the most part alleviated from the Mega Backdoor Roth Solo 401k strategy because IRAs including those with nondeductible funds are not taken into account when processing the Mega Backdoor Roth Solo 401k, so it is easier to figure out the taxes you may owe on the conversion.
Taxes generally don’t apply to the Mega Backdoor Roth Solo 401k conversion unless there are earnings which can technically be transferred to the pre tax solo 401k to a traditional IRA. Thus, it is generally best to process the conversion as soon as possible after making the voluntary after-tax solo 401k contribution to limit the taxes due on the earnings since the entire amount in the voluntary after-tax solo 401k is required to be converted. While the gains in the voluntary after-tax solo 401k may be transferred to an IRA or to the pre tax solo 401k, it is generally best to also convert the gains as well and to just pay taxes on the gains if the gains are small so that they can start growing tax free once inside the Roth IRA or the Roth solo 401k.
Quickt Items to Know
- Unlike IRAs, Form 8606 does not apply to voluntary after-tax solo 401k contributions because they are already separately tracked in the solo 401k by holding them in a bank account or brokerage account in the name of the solo 401k with the label “voluntary after-tax”.
- The voluntary after-tax solo 401k contribution can be converted as soon as the contribution clears.
- The voluntary after-tax solo 401k funds may be converted to a Roth IRA or the Roths solo 401k.
- The earnings in the the voluntary after-tax solo 401k may be converted to the Roth solo 401k, to the Roth IRA, or they can be directly rolled over to the pre tax solo 401k or to a traditional IRA.
