After Tax to Roth Solo 401K In-Plan Conversion Form

Each time you process an in-plan conversion of AFTER-TAX solo 401k funds to Roth Solo 401k funds, please complete the following on-line form.

  • If each participant is converting funds, please submit a separate on-line conversion form for each participant.
  • It is best to submit this on-line conversion form once you have converted/moved the funds to ensure all gains are accounted for.
  • We will issue the Form 1099-R in February 2027 to report the year 2026 conversion.

COMPLIANCE NOTE:

Conversions are reported in the year that the funds are actually moved over to the Roth account. 

The solo 401k contribution rules are different from the  conversion rules. Contributions can be made by your business tax return due date plus any timely filed extension for the prior year.

In sum, the voluntary after-tax solo 401k conversion will be nontaxable regardless if  you convert the after-tax contributions that were made in 2025 or in 2026 for 2025.

You can also access the same form at the following link: After Tax to Roth Solo 401K In-Plan Conversion Form

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