Can I do a Mega Backdoor Roth Solo 401k for 2021 in 2022?


I was very busy at the end of last year and didn’t set up a Solo 401k by 12/31/2021.  Can I still set up a Solo 401k plan in 2022 and make Mega Backdoor Roth contributions?  Please note that I own my own business with no employees.  I operate my business as a single-member LLC with income reported on my 1040.


While the IRS does not explicitly state that a self-employed individual such as yourself can still set up a Solo 401k and make Mega Backdoor Roth Solo 401k contributions for 2021, one may reasonably conclude that Mega Backdoor Roth Solo 401k contributions may still be made for 2021 if the plan is established and the contributions are made on or before your business tax return deadline in 2022 including a timely filed extension.

Secure Act Extended the Deadline

First, at the end of 2019, Congress enacted the Secure Act which extended the Solo 401k establishment deadline to the business tax return deadline (including timely extensions).
Under this law, one may consider a Solo 401k to have been adopted as of 12/31/2021 as long as the plan was established on or before the business tax return deadline (including timely filed extension) in 2022.

Specifically, the SECURE Act amends 26 U.S. Code § 401(b) to add a new section providing that “if an employer adopts a stock bonus, pension, profit-sharing, or annuity plan after the close of a taxable year but before the time prescribed by law for filing the return of the employer for the taxable year (including extensions thereof), the employer may elect to treat the plan as having been adopted as of the last day of the taxable year.” [emphasis added] See

Elective Deferrals

In spite of the Secure Act, the IRS provides that a self-employed individual must elect to make employee contributions (also known as elective deferrals) by December 31st and then can deposit the contribution by the business tax return deadline including timely filed extension.  See the statement of page 4 of IRS Publication 560 HERE.
As a result of this requirement, it is widely understood that if a self-employed individual adopts a Solo 401k plan after the end of the tax year but before his/her business tax return deadline he/she will not be able to make employee contributions for such year but can still make employer non-elective (profit-sharing) contributions.
Just like employer non-elective (profit-sharing) contributions, IRS Publication 560 is silent on the need to elect to make a voluntary after-tax contribution by the end of the tax year.

Contribution Types: Elective Deferrals & Voluntary After-Tax

Moreover, elective deferrals and voluntary after-tax contributions are clearly distinct types of contributions (e.g. consider that they are subject to different contribution limits under IRC 402(g) and IRC 415(c) respectively), such that one may reasonably conclude that the reference to “elective deferrals” in IRS Publication 560 also refers to voluntary after-tax contributions (e.g., one may reasonably conclude that if the IRS wished to require that voluntary after-tax contributions were elected by the end of the tax year, IRS Publication 560 would state so).

Tags: , , , , , , , , ,

About George Blower

I have the privilege of educating our clients about our products and services so that they can make informed and confident decisions about their financial future. Prior to joining My Solo 401k Financial, I served as the general counsel for a subsidiary of a Fortune 500 financial services company. Learn more about George Blower and My Solo 401k Financial >>

Post a Comment

Your email is never published nor shared. Required fields are marked *

You may use these HTML tags and attributes <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>



  • 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?