Using a Solo 401k to Isolate IRA After-Tax Funds for Backdoor Conversion of IRA to Roth IRA

For those with IRAs that contain both pretax and non-deductible IRA contributions, and are planning to just convert the after-tax IRA (non-deductible IRA fund) to a Roth IRA, a solo 401k plan may be a good way to isolate the pretax IRA funds so that just non-deductible IRA funds can be subsequently converted to a Roth IRA.

Only pre-tax IRA funds can  transferred to company plans such as a solo 401k. By transferring the pre-tax IRA funds to a solo 401k plan, you will be able to take full advantage of the backdoor Roth IRA strategy. Once you transfer the pretax IRA funds to the pretax solo 401k bucket, the remaining basis in the IRA can be converted to a Roth IRA tax free.


John is self-employed and opens a solo 401k plan for his self-employed business.  He has $20,000 in a traditional IRA of which $5,000 consist of non-deductible IRA contributions. John transfers $15,000 of the IRA funds to a solo 401k plan. Therefore, he has isolated the $5,000 of non-deductible (after-tax) IRA funds which he then converts to a Roth IRA. Because the $5,000 is considered after-tax IRA funds, he does not owe any taxes on the Roth IRA conversion.

About Mark Nolan

Each day I speak with energetic entrepreneurs looking to take the plunge into a new venture and small business owners eager to take control of their retirement savings. I am passionate about helping others find their financial independence. Having worked for over 20 years with some of the top retirement account custodian and insurance companies I have a deep and extensive knowledge of the complexities of self-directed 401ks and IRAs as well as retirement plan regulations. Learn more about Mark Nolan and My Solo 401k Financial >>


  • Popular Video

  • ROBS 401k Funding Process

  • Solo 401k Contributions Including Mega

  • Checkbook IRA LLC

  • About MySolo401k

    We help our clients take control of their retirement money. Our products and services provide our clients the freedom to invest their retirement savings in their own business as well as alternative investments such as real estate, private companies, promissory notes, precious metals, tax liens and equities.
    Learn more

    Connect with us

  • We’re here to help.

    Call: 800-489-7571


    8:00 am - 4:00 pm PT

    Why us?